Terms of Use

1Agreement to these terms

These Terms of Use (“Terms”) are a legal agreement between you and Zydeno, the developer of Molveth (“we”, “us”). They apply to the Molveth app for Android, its updates and everything it shows or produces (together, “the app”). By installing, opening or using the app you accept these Terms. If you do not accept them, do not use the app and uninstall it.

The Privacy Policy explains how the app handles data and forms part of these Terms. If we offer optional features under additional terms in the future, for example paid features, those terms will be shown to you before you accept them and will apply together with these Terms.

You must be old enough to enter into a binding contract where you live, or use the app with the consent and supervision of a parent or guardian who accepts these Terms for you. If you use the app for an organisation, you confirm that you may accept these Terms on its behalf; the consumer-protection provisions of these Terms apply only to consumers.

2What Molveth provides

Molveth is an offline chemistry study desk: an interactive periodic table with element properties, isotopes, orbital models and trend plots; practice questions with spaced review; an equation balancer; and calculators for molar mass, stoichiometry and limiting reagent, solution preparation and dilution, pH, gas laws, particles and moles, and empirical and molecular formulas; plus a local notebook of worksheets, a glossary and reference notes, printable and exportable sheets, and manual backups. Interface languages do not imply that every term or exam convention of every country is covered.

Features, data coverage and device support depend on the version you install. Descriptions of possible future features do not make them available in the current version.

3Not professional advice; no safety-critical use

The app is a tool to help you plan and calculate. It does not give professional, engineering, legal or other expert advice, and using it does not create a professional relationship with us. You remain responsible for your inputs, for how you interpret the results and for what you decide to do.

Do not use the app as the only basis for a decision where an error could cause death, personal injury, damage to property or the environment, or legal or financial loss, and do not use it in a safety-critical system, in an emergency or to control equipment. Molveth is a study and calculation aid, not a laboratory protocol, a hazard or safety-data source, a reaction-outcome predictor, or a medical, toxicological, environmental or regulatory reference. A balanced equation shows conservation of atoms and charge; it does not show that a reaction occurs, is safe or gives a stated yield. The reference data are compiled from open datasets, are not an official or certified publication, and may contain errors or gaps.

4Licence to use the app

Subject to these Terms, we grant you a limited, personal, revocable, non-exclusive, non-transferable and non-sublicensable licence to download, install and use the app on Android devices you own or control, for your own purposes (study, teaching and preparing your own coursework). The app is licensed to you, not sold.

Except where these Terms, an open-source licence or mandatory law allow it (for example decompiling for interoperability where the law permits), you may not: copy, modify, translate or create derivative works of the app; decompile, disassemble or reverse-engineer it; rent, lend, sell, sublicense, distribute or publish it, or make it available for use by others over a network; remove or change any copyright, trademark or legal notice; or get around any technical limit of the app, including any future purchase, licence or advertising mechanism.

Open-source components and fonts in the app are licensed under their own licences, listed in the app under About → Open-source licenses. Those licences prevail for those components, and nothing in these Terms limits the rights they give you.

5Educational use; reference data may contain errors

Molveth is designed for learning. Its element data, isotope data, models and explanations are compiled from open datasets and published conventions, simplified for teaching, and can contain errors, omissions, rounding differences or values that differ from the edition of a textbook, data book or standard your course uses. Unknown values are shown as unknown, and some properties are estimated or predicted. Check primary references before relying on a value.

Calculators apply ideal or textbook models (for example the ideal gas law, ideal dilution and complete-reaction stoichiometry) to the values you enter and to the stated mass basis, rounding and units. Results depend on your inputs, units and the options you choose, and are not guaranteed to match a published, graded or instrument-measured answer. An equation that is formally balanced is not thereby shown to occur, to be safe or to give a stated yield.

The app does not predict reaction products, supply procedures, or give hazard, toxicity, dosage, first-aid, environmental or regulatory information. It is not a substitute for your instructor, a laboratory manual, a safety data sheet or a qualified professional.

6Laboratory work and safety

Quantities shown for solutions, dilutions, gases or reagents are arithmetic on the numbers you provide. The app does not know the hazards of any substance, the compatibility of any mixture, the purity or hydration state of your actual reagent, or the conditions in your laboratory. Preparing or handling chemicals can cause injury, fire, explosion, poisoning or environmental harm, and you carry out any such activity at your own risk.

7Data sources and trademarks

Element scalars come from the Blue Obelisk Data Repository (CC0 1.0 dedication, with historical MIT notices retained); element names, identifiers and further structured facts come from Wikidata (CC0 1.0); some density values derive from the public-domain periodictable package (P. A. Kienzle; values originally compiled in the CRC Handbook of Chemistry and Physics); the boiling points of beryllium, silicon and manganese come from the Los Alamos National Laboratory periodic table (© Copyright 2021 Triad National Security, LLC), reproduced with attribution. Source, version, date and licence for each value are listed in the app under About, Sources, and in the bundled notices. The requested citation for the Blue Obelisk Data Repository is Guha et al., J. Chem. Inf. Model. 46(3), 991–998 (2006), doi:10.1021/ci050400b.

IUPAC, NIST, CIAAW, PubChem, Wikimedia, Wikidata, the Blue Obelisk project, Los Alamos National Laboratory, Triad National Security, LLC, the U.S. Department of Energy, CRC Press and other organisations named in the app are mentioned only to identify a convention or a data source. Molveth is not affiliated with, sponsored by or endorsed by any of them, and no value is an official, certified or approved publication of any of them.

8Coursework, exams and academic integrity

Many courses, schools and examinations restrict calculators, phones and reference tools. You are solely responsible for knowing and following those rules. Molveth is not endorsed by, and makes no statement about, any examination board, school or curriculum, and no particular result, grade or learning outcome is promised. Practice questions are original study material and do not reproduce any examination.

9Exports, backups and print scale

Review the generated preview, the units, the dataset version and the page size before saving or printing. Exported PDFs and text summaries reflect the settings and values you select; fonts, recipient apps and printer drivers can affect appearance and clipping. A PDF or text summary is not an editable backup. Only supported archive formats and schema versions can be restored.

Keep a full archive in a location you trust, check that it can be opened, and do not rely on the app as the sole copy of work you cannot recreate.

10Your content and responsibilities

You are responsible for the formulas, values, notes and other material you enter, import, export, print or share, for having the necessary rights to them, and for reviewing anything you hand in or give to another person. Do not present a Molveth result as an official, certified, laboratory-verified or measured value. Do not put other people’s personal information in worksheet notes unless you have the right to do so.

11Local data, backups and external services

Your saved app data stays on your device unless you choose to export, share or print it. There is no developer account, server copy or automatic cloud backup. Imports can add records or replace existing data after confirmation; review the preview and export your current data first. Recovery and integrity checks cannot guarantee recovery from hardware failure, storage exhaustion, corruption or an incompatible archive. Clearing app storage or uninstalling removes private working data.

The system file picker may offer cloud providers; sharing passes a generated file or text to your chosen app; printing passes a document to your selected print service and printer. These providers can store or transmit your file under their own terms. Copies saved outside the app, sent to a recipient or printed are not removed by Delete all. See the Privacy Policy for details.

12Fonts and open-source components

The app bundles the Commissioner and B612 typefaces under the SIL Open Font License 1.1; AndroidX, Jetpack Compose, Kotlin and kotlinx libraries under the Apache License 2.0; and the open datasets described above under their own terms. The licence texts and notices are available in the app under About, Sources and licences, and work offline. Short interface sounds and orbital models in the app were generated by Zydeno.

Open-source licences prevail for the components they cover. These Terms do not grant permission to resell a font file, library or dataset contrary to its own licence. Android, Google Play and other third-party names identify their respective products and services; their use does not imply endorsement or affiliation.

13Acceptable use

Use the app lawfully and considerately. Do not use it to cheat where a rule forbids tools, to mislead a teacher, employer, customer or regulator about the source or reliability of a calculation, or to plan anything harmful or unlawful. You remain responsible for any experiment, product, instruction or document you produce.

14Your content and our materials

You retain the rights you hold in your own notes, worksheet titles and other content. Creating or exporting work in Molveth does not transfer ownership of it to Zydeno.

The app, brand, interface artwork, bundled explanations, practice questions and compiled data presentation are protected by intellectual-property law, subject to the licences of the open data described above, which remain applicable to the underlying facts. You may print and share the worksheets the app generates for your own study or teaching. This does not grant a right to extract and redistribute the practice question bank or the explanatory text as your own course or product.

15Price, payments, ads and future paid features

Current version. The current version of Molveth is provided free of charge, without ads and without in-app purchases or subscriptions. This describes the current version only. It is not a promise that the app, or any feature of it, will remain free of charge or free of ads.

Possible changes. We may at any time introduce advertising; offer paid features, in-app purchases, subscriptions or a paid edition; change which features are free; and set or change prices. Features that are free today may require payment in a future version. We will describe such changes in the store listing and release notes, and in the Privacy Policy where they affect data.

Purchases. Any purchase will be made through Google Play and processed by Google under the Google Play Terms of Service and its payment policies. Prices are shown in Google Play before you buy, including taxes where applicable. Subscriptions renew automatically until you cancel them in Google Play; cancelling stops future renewals. Refunds follow Google Play’s refund policies and your mandatory consumer rights, such as the right of withdrawal in the EU and the UK. Where you ask for immediate access to digital content during a withdrawal period, you may lose that right to the extent the law allows, and you will be asked to confirm this before you buy. You are charged only if you choose to buy something.

Ads. If the app shows ads, they are supplied by third parties. We are not responsible for the content of ads or for the products and services advertised, and any dealings with advertisers are between you and them.

Price changes. We may change prices for future purchases at any time. For an active subscription, we will announce a price increase as Google Play and the law require, and you can cancel before it applies.

16Disclaimer of warranties

Element data, models, explanations, practice questions and calculation results can contain errors. We do not promise that data are complete or current, that results match a textbook, an examination mark scheme or a measurement, that practice improves any grade, or that the app is free of defects, compatible with every device or able to recover lost data.

17Limitation of liability

To the extent the law permits, we are not responsible for any loss or harm arising from reliance on reference data or calculation results; any laboratory, classroom, industrial or domestic activity carried out using the app; wasted materials, equipment or time; academic penalties or failed assessments; loss or corruption of worksheets, practice records or archives; or disclosure through a destination you select. The limitations and mandatory exceptions below govern this clause.

18Your rights as a consumer

If you use the app as a consumer, you benefit from the mandatory consumer-protection rules of the country where you live, and nothing in these Terms affects them. In particular:

• EU and EEA: your statutory rights, including those on the conformity of digital content and digital services under the national rules implementing Directive (EU) 2019/770 where they apply, and mandatory product-liability rules, remain unaffected.
• United Kingdom: your statutory rights, including under the Consumer Rights Act 2015, remain unaffected.
• Australia: our services come with guarantees that cannot be excluded under the Australian Consumer Law. Where the law allows us to limit our liability for failing to meet a consumer guarantee for services that are not of a kind ordinarily acquired for personal, domestic or household use, our liability is limited to supplying the services again or paying the cost of having them supplied again.
• New Zealand: if you acquire the app for business purposes, you agree that the Consumer Guarantees Act 1993 does not apply, to the extent the law permits.
• United States and Canada: some states and provinces do not allow the exclusion of implied warranties or the limitation of incidental or consequential damages, so some of the exclusions above may not apply to you. In Québec, the mandatory provisions of the Consumer Protection Act apply.

19Indemnity

To the extent permitted by law, you agree to indemnify and hold harmless the developer against claims, liabilities, damages, losses and reasonable costs, including reasonable legal fees, brought by third parties and arising out of (a) the worksheets, notes, calculations and exports you create, print or share, including anything you submit for coursework or provide to others, and any laboratory or other real-world activity you carry out, (b) your breach of these Terms, (c) your violation of any law or of the rights of others, or (d) output of the app that you provide to another person, such as a client or employer. This does not apply to the extent a claim is caused by our own breach of these Terms or our negligence, or where local consumer law does not allow it.

20Changes, availability and termination

To the extent the law allows, we may change, update, add or remove features, change data sources, and suspend or discontinue the app, in whole or in part or in any country, at any time. We are not obliged to provide updates, maintenance or support, except where mandatory consumer law requires updates to keep the app in conformity.

You may stop using the app at any time by uninstalling it. Your licence ends automatically if you materially breach these Terms, and we may end or suspend it where the law requires. When it ends, you must stop using the app and uninstall it. Your data stays on your device under your control, so export what you need first.

Provisions that by their nature should continue after these Terms end continue to apply, including those on intellectual property, disclaimers, limitation of liability, indemnity, governing law and general provisions.

21Google Play

You obtain the app through Google Play. Your download, and any purchase you make, is also governed by the Google Play Terms of Service and Google’s policies. Where these Terms conflict with Google Play’s terms on the distribution, billing, refunds or licensing of apps obtained from Google Play, Google Play’s terms prevail to the extent of that conflict.

These Terms are between you and the developer only, not Google. Google is not responsible for the app or its content and has no obligation to provide maintenance or support for it. Android and Google Play are trademarks of Google LLC.

22Governing law and disputes

These Terms, and any dispute or claim arising out of or in connection with them or the app, including non-contractual disputes, are governed by the law of the country in which the developer is established, without regard to its conflict-of-laws rules. The United Nations Convention on Contracts for the International Sale of Goods does not apply.

The courts competent for the place where the developer is established have jurisdiction. If you are a consumer, you keep the protection of the mandatory provisions of the law of your country of residence, and you may bring proceedings in the courts of that country where that law allows it.

Before starting formal proceedings, please write to [email protected] and give us at least 30 days to try to resolve the issue informally. This does not affect any time limit that applies to you by law or your right to use an alternative dispute-resolution body available to consumers in your country.

23General provisions

• Entire agreement. These Terms, the Privacy Policy and any additional terms you accept for optional features are the entire agreement between you and us about the app.
• Severability. If a provision is found invalid or unenforceable, it applies to the maximum extent permitted and the rest remains in effect.
• No waiver. Not enforcing a provision is not a waiver of the right to enforce it later.
• Assignment. You may not transfer your rights or obligations under these Terms. We may transfer ours, for example together with the app to another developer; where the law requires, this will not reduce your rights as a consumer.
• Events beyond our control. We are not responsible for failure or delay caused by events beyond our reasonable control, such as outages of networks, devices or third-party services, natural disasters or acts of authorities.
• Export and sanctions. You agree to use the app in compliance with applicable export-control and sanctions laws.
• No third-party rights. No one other than you and us may enforce these Terms.
• Notices. We may give notices in the app, in its store listing or release notes, or on this page. You can send notices to [email protected].
• Language. These Terms are written in English, which is the binding version. A translation, if offered, is for convenience only, unless the law of your country requires otherwise.

24Changes to these terms

We may update these Terms, for example when we change the app, introduce ads or paid features (§15), or when the law changes. The effective date and version at the top of this page show which version applies, and the version history (§25) summarises the changes.

For material changes we give reasonable notice before they take effect, for example in the release notes or in the app. If you keep using the app after the changes take effect, you accept the updated Terms; if you do not agree, stop using the app and uninstall it. Changes do not apply to disputes that arose before they took effect.

25Version history

26Contact

• Developer: Zydeno, the developer of Molveth on Google Play
• E-mail: [email protected]
• Website: zydeno.com

See also the Privacy Policy.