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Numio Calculator

rag-creation
Tools
Version
1.0.7
Size
1.4 MB
Requires
Android API 24+
4.1 / 5 · 17,906 ratings 112,424 downloads
Download APK

Updated Oct 14, 2026

Quick answer

A clean, open-source calculator with live results and unit conversion

Numio is a clean, minimal calculator built with Kotlin and Jetpack Compose. No ads, no tracking, no internet permission — it never needs to talk to the outside world.

Features:

* Clean, minimal design with retro circular keys * Live results — see the answer as you type * Scrollable expression display, so long numbers are never truncated * Calculation history saved locally with a Room database * Built-in unit converter — Length, Weight, Area, Volume, Temperature, Time, Speed, Pressure * Theme customization — 12 preset accent colors plus custom hex input * Your chosen theme color is remembered across sessions * Hand-drawn custom app icon * A small hidden easter egg * 100% offline — nothing ever leaves your device

This is a first solo project, built from scratch and open-sourced so anyone can use, inspect, or contribute to it.

Screenshots

Numio Calculator screenshot 1
Numio Calculator screenshot 2
Numio Calculator screenshot 3
Numio Calculator screenshot 4

What’s new

- Fixed a crash when switching converter categories (for example Volume to Temperature)
- Converter shows "Number too large" or "Not a number" instead of crashing or staying blank, and accepts a comma as the decimal point (1,5)
- Converter result stays visible above the keyboard
- Landscape: the result is no longer hidden and key labels fit their buttons
- Custom colour: codes like GGGGGG now show an error
- Results like 0.1 + 0.2 now show 0.3

How to install

  1. Download the APK from the button at the top of this page.
  2. Allow “Install unknown apps” for your browser or file manager only, not for every app.
  3. Open the downloaded file and confirm the installation.
  4. If installation fails with “App not installed,” remove an earlier build of the same app first. A signature conflict is the usual cause.

Data safety

  • Every file is checked against its published SHA-256 before it is listed.
  • Files are scanned for malware on every update.
  • The permissions each app requests are listed on its own page.
  • Read the full safety policy for how we test, flag, and delist files.

Frequently asked questions

What is Numio Calculator?
A clean, open-source calculator with live results and unit conversion
Who develops Numio Calculator?
Numio Calculator is developed by rag-creation.
Which Android version does Numio Calculator require?
Numio Calculator requires Android API 24 or later.
What is the current version of Numio Calculator?
The synchronized F-Droid version is 1.0.7.
Which license does Numio Calculator use?
The signed F-Droid metadata lists GPL-3.0-only.
Where is the source code for Numio Calculator?
https://github.com/rag-creation/numio

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