216 tools. Zero network permissions.

Name: ToolXStack
Author: SM NexStudio

JSON and JWT, hashes and regex, unit and loan calculators, colour tools and more, in one fast app. ToolXStack has no internet permission at all, so what you paste never leaves your phone.

Tools: 216
Categories: 10
Network permissions: 0

Download APK Source on GitHub Privacy policy

Why ToolXStack

One app instead of a drawer of ad-heavy single-purpose apps and web converters that see everything you paste.

Nothing can leave
The release build strips Android’s INTERNET permission, so the system itself refuses any network request. A test in the build checks it stays that way.
Works anywhere
On a flight, underground or in a locked-down data centre. Every tool runs on your phone with no connection.
Everything in one place
57 developer tools, 32 unit converters, 22 finance calculators and more, behind one search that understands emi, b64 and dob.
Learn as you go
Each tool has a short article with the formula and a worked example, plus 37 offline guides on HTTP, regex, cron, Git, hashing and more.
Fits every screen
Phones, foldables, tablets and Chromebooks. Wide screens get two panes, and a keyboard works: Enter runs a tool, Escape closes a sheet.
Free, with no catch
No ads, no in-app purchases, no pro tier and no account. Apache-2.0 on GitHub.

216 tools in 10 categories

The tools developers reach for every day, next to the calculators everyone else needs.

JSON, XML and YAML: format, minify, validate, convert, and query with JSONPath.
JWT: decode, inspect claims and check expiry, without pasting a token into a website.
Hashes and HMAC: MD5, SHA-1, SHA-256, SHA-384 and SHA-512, checked against published test vectors.
Text: diff, regex tester, find and replace, SQL formatter, case converters and counters.
Finance: EMI with a full amortisation table, SIP, CAGR, GST, FD and RD.
Colour: HEX, RGB and HSL, harmonies, and a WCAG contrast checker.

57DeveloperJSON, XML, YAML, JWT, hashes, regex
28CalculationScientific, stats, fractions
21Geometry2D and 3D shapes, volume
32Unit ConverterLength, mass, temperature, data
22FinanceEMI, SIP, CAGR, GST, FD
8HealthBMI, BMR, hydration, pace
23Text UtilitiesCounters, case, line tools
10Color ToolsHEX, RGB, HSL, contrast
10RandomizerDice, coin, picker
5Date & TimeAge, duration, time zones

Your data stays on your device

ToolXStack collects nothing, because it can’t send anything. The privacy policy is short for a reason.

Read the privacy policy

Blocked by Android, not by promiseNo INTERNET or network-state permission. The only permission is vibrate, for haptics.
No analytics or crash reportsNo tracking SDKs and no behaviour logging.
Your inputs are never savedFavourites and recents keep only tool IDs and times, never what you typed.
Clipboard only when you tapToolXStack reads or writes the clipboard only when you press a button.

Install in a minute

ToolXStack is shared on GitHub rather than an app store, so there is no store account and no store tracking.

Download the APK
Open the latest release on your phone and download the .apk file.
Allow the install
Tap the file. If Android asks, allow your browser or file manager to install apps, just this once.
Check it, if you like
Each release has a SHA-256 checksum. Run sha256sum -c ToolXStack-vX.Y.Z.apk.sha256 to confirm your download is the published file.

Questions

Does it really work without internet?

Yes. Every tool runs on your phone, and the app has no permission to use the network at all.

Is anything I paste stored?

No. Favourites and recents store only which tool you used and when, never your inputs or results.

Why is it on GitHub and not the Play Store?

Releases on GitHub come with a SHA-256 checksum for every build, so you can check exactly what you install, and there is no store in between collecting data.

Which Android versions are supported?

Android 13 (API 33) and newer, on phones, foldables, tablets and Chromebooks that run Android apps.

Is it really free?

Yes. ToolXStack is free and open source under Apache-2.0, with no ads, subscriptions or in-app purchases.

How do I report a bug or ask for a tool?

Open an issue on GitHub. Pull requests are welcome too.