Effective date: [To be filled before publishing]
Developer: ZADIO EOOD, registered in the Republic of
Bulgaria (EU). Registered office: Ploshtad Han Kubrat 1, Ruse,
Bulgaria.
Contact:
app@zadio.bg
1. Acceptance of terms
By downloading, installing, or using SingingNumbers ("the App"), you agree to these Terms of Service. If you do not agree, do not use the App.
2. Description of service
SingingNumbers is a free, fully offline calculator application that
plays a unique musical tone for each digit (0–9) entered.
Operators (+, −, ×,
÷) do not produce a tone themselves; they shape
the articulation of the next digit's note (accent for
+, soft for −, legato for
×, rest for ÷). Pressing
= is also silent and triggers playback of the full
expression plus the resulting digits as a short melody. The App
ships six user-facing screens reachable from the navigation
drawer — Calculator (with a Big Calculator
mode that extends the keypad to 24 notes), Saved,
Scales, Octaves,
Instruments, and Settings
— and the App:
- Performs arithmetic locally on your device.
- Synthesises audio in real time on your device using Google Oboe and Android's audio output APIs (no microphone access).
- Requires no internet connection.
- Collects, stores, and transmits no personal data (see the Privacy Policy for the on-device-only preference and saved-calculations files).
- Contains no advertisements.
- Offers no in-app purchases or subscriptions.
3. License
SingingNumbers is licensed under the Apache License, Version 2.0. You are granted a free, non-exclusive license to use the App for any lawful purpose. The Apache 2.0 license also grants any recipient of the App's source code the right to view, modify, and redistribute it under the license's terms. A public source-code repository is not currently available for this version of the App; if one is published in the future, the URL will be added here.
4. No warranty
THE APP IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NONINFRINGEMENT.
The developer does not warrant that:
- The App will meet your specific requirements.
- The App will be uninterrupted, timely, secure, or error-free.
- Calculation results will be accurate in all circumstances.
- Audio playback will be reliable on every device, audio driver, or Bluetooth headset combination.
- Any errors in the App will be corrected.
5. Limitation of liability
IN NO EVENT SHALL THE DEVELOPER BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES.
The App is intended for casual and educational use (everyday arithmetic, musical experimentation, accessibility-friendly key feedback). Do not rely on it for:
- Financial calculations requiring guaranteed precision or audit trail.
- Scientific or engineering computations whose correctness is critical.
- Medical dosage or clinical calculations.
- Any purpose where a calculation error could cause physical, financial, or reputational harm.
6. Age rating
The App is rated Teen (13+) on Google Play. Younger users may use the App safely (since no data is collected and there are no ads or in-app purchases), but the listing's age rating should be respected when allocating App access to a child's device or account.
7. User responsibilities
You agree to:
- Use the App in compliance with all applicable laws.
- Not use the App for any unlawful purpose.
8. Termination
These terms remain in effect while you use the App. You may terminate by uninstalling the App from your device. Because the App collects no data and has no account system, uninstallation results in complete removal — there is nothing to delete on any server. The on-device preference files and the (opt-in) saved-expressions file described in the Privacy Policy are also removed automatically when the App is uninstalled.
9. Changes to terms
The developer reserves the right to modify these Terms at any time. Updated terms will be posted at this URL with a new "Effective date". Continued use of the App after changes constitutes acceptance of the new terms.
10. Governing law
These Terms shall be governed by, and construed in accordance with, the laws of the Republic of Bulgaria, without regard to its conflict-of-laws rules. The competent courts at the seat of the Developer (Ruse, Bulgaria) shall have exclusive jurisdiction over any dispute arising out of or in connection with these Terms, except where mandatory consumer-protection rules of the user's country of habitual residence grant the user the right to bring proceedings in their local courts.
11. Google Play
If you downloaded the App from Google Play, Google Play's Terms of Service also apply. In case of conflict, Google Play's Terms prevail for matters within Google Play's scope.
12. Contact
Questions about these Terms should be directed to:
app@zadio.bg