Terms of Service
These Terms of Service ("Terms") govern your use of Callisto ("App"), developed and operated by Sebastian Pichler, Lindengasse 4, 4040 Linz, Austria ("Developer"). By downloading, installing, or using the App you agree to be bound by these Terms.
1. Description of the App
Callisto is a Python development environment for Android. It allows you to create, edit, and execute Jupyter notebooks and Python scripts entirely on your device — no internet connection, no server, and no user account are required.
2. Acceptance of Terms
By using the App you confirm that you have read, understood, and agree to these Terms and to our Privacy Policy (available under Settings → About → Privacy Policy). If you do not agree, please do not use the App.
If you are under 18 years of age, you confirm that you have obtained the consent of a parent or legal guardian to use the App and to agree to these Terms on your behalf.
3. Licence to use the App
Subject to these Terms, the Developer grants you a personal, non-exclusive, non-transferable, revocable licence to install and use the App on Android devices you own or control, solely for your own lawful personal or professional purposes.
This licence does not include the right to sublicence, sell, resell, copy, modify, or distribute the App or any part of it except as expressly permitted by applicable law.
4. Free and paid features
Free tier: The App is free to download and use. The free tier includes all core notebook and scripting functionality together with a base set of pre-installed Python packages.
Paid tier ("Lifetime Unlock"): Additional Python packages and premium features are available as a one-time in-app purchase. The Lifetime Unlock is a single payment with no recurring charges. The purchase is processed by Google LLC through the Google Play Store and is governed by Google's Terms of Service, Google Play Developer Distribution Agreement, and applicable payment terms. The Developer does not process or store payment information. Once purchased, the Lifetime Unlock is tied to your Google Play account and may be restored on other devices using the same account.
Refunds: Requests for refunds are handled by Google Play in accordance with Google's refund policies. The Developer cannot process refunds directly.
5. On-device code execution and user responsibility
All Python code you write and execute in the App runs exclusively on your device. The Developer has no access to your notebooks, scripts, data files, or any outputs produced by your code.
You are solely responsible for the code you write and execute and for any effects that code may have on your device, your files, or any third-party services you call from your code. The Developer accepts no liability for damage to your device, loss of data, or any other harm resulting from code you choose to run.
You agree not to use the App to write or execute code that is unlawful, harmful, abusive, or that infringes the rights of third parties.
6. Intellectual property
The App, its user interface, graphics, and bundled assets (excluding third-party open-source components) are protected by Austrian and international copyright law and are the intellectual property of the Developer or their respective licensors.
Open-source components used in the App are listed under Settings → About → Open Source Licences (also available here) and are subject to their respective licences.
You may not decompile, reverse-engineer, disassemble, copy, modify, or redistribute the App or any part of it, except to the extent expressly permitted by applicable law (including § 40d UrhG).
7. Disclaimer of warranties
To the maximum extent permitted by applicable Austrian and EU law, the App is provided "as is" and "as available" without warranties of any kind, express or implied, including without limitation any implied warranties of merchantability, fitness for a particular purpose, accuracy, or non-infringement.
The Developer does not warrant that the App will be uninterrupted, error-free, or free of harmful components, or that defects will be corrected.
Statutory rights you have as a consumer under Austrian law (Konsumentenschutzgesetz, KSchG) and applicable EU law cannot be excluded or limited by these Terms and remain unaffected.
8. Limitation of liability
To the maximum extent permitted by applicable Austrian and EU law, the Developer's total aggregate liability to you for any claims arising out of or related to these Terms or the App is limited to the amount you actually paid for the App in the twelve months preceding the event giving rise to liability (or zero if you use only the free tier).
The Developer is not liable for indirect, incidental, special, consequential, or punitive damages, including loss of data, loss of profit, loss of business opportunity, or loss of goodwill, arising out of your use of or inability to use the App, even if the Developer has been advised of the possibility of such damages.
Nothing in these Terms excludes or limits liability for (i) death or personal injury caused by negligence, (ii) fraud or fraudulent misrepresentation, or (iii) any other liability that cannot be excluded or limited under applicable Austrian or EU law.
9. Updates and changes to the App
The Developer may release updates to the App from time to time. Updates may change or remove features. Where a paid feature is materially degraded without cause, the Developer will use reasonable efforts to notify users and provide a remedy.
10. Termination
These Terms remain in effect until terminated. Your right to use the App terminates automatically if you breach any provision of these Terms. You may terminate these Terms at any time by deleting the App from your device. Termination does not entitle you to a refund of any amounts paid.
11. Changes to these Terms
The Developer may revise these Terms from time to time. The current version is always available in the App under Settings → About → Terms of Service. Continued use of the App after revised Terms are made available constitutes your acceptance of the revised Terms.
12. Governing law and jurisdiction
These Terms are governed by Austrian law (Allgemeines bürgerliches Gesetzbuch, ABGB). Where you are a consumer resident in another EU member state, the mandatory consumer-protection provisions of your country of residence apply to the extent they provide greater protection than Austrian law.
Any dispute arising out of or relating to these Terms or the App shall be subject to the exclusive jurisdiction of the competent courts in Austria, subject to the mandatory consumer-venue rules under § 14 KSchG and Regulation (EU) No 1215/2012 (Brussels Ibis Regulation).
The European Commission provides an online dispute resolution platform at https://ec.europa.eu/consumers/odr. The Developer is not obliged to participate in alternative dispute resolution proceedings and does not currently do so, but you may contact us at any time at the address below.
13. Contact
Sebastian Pichler
Lindengasse 4
4040 Linz
Austria
dev@callistoapp.eu