A regular expression matching game
About this app
Try and find a regular expression (Perl style) to match certain strings, while not matching others.
Currently there are three game modes, that can be selected and configured from the settings. These generate Tasks, set limits to how many characters may be used, and which solutions are successful an which are not.
All game modes are based on the same concept: the Task to solve will be displayed on the screen as soon as possible (near immediately for Random game, longer for REDB game), and then the user has to enter a regular expression to solve the task. As soon as it fits to conditions, it will be automatically submitted, and the next task will generate - no questions asked. The user will be notified in case s?he rises up a level.
Licensed under GPL-2.0-or-later.
What's New in v1.3.1
Imported from the F-Droid repository index.
Version history
Dec 4, 2016 · 2 MB · Android API 16–24 · code 5
Imported from the F-Droid repository index.
SHA-256 36a6bde6bc0704f21dd57a8737a9054801e8b8cf74668be35003ce7aa7b989c8
Nov 1, 2016 · 2 MB · Android API 16–24 · code 4
Imported from the F-Droid repository index.
SHA-256 42528171705a99c0eaca92220dda8c329eca723dccebcfec1c72650dbadefbd9
Nov 16, 2015 · 1.2 MB · Android API 16–22 · code 3
Imported from the F-Droid repository index.
SHA-256 4774e18fd0dfe0dbed67cff10bbd203d1a2b5ede9614f81ee2c7cb688551b53a
Will it run on your device?
73%
- Runs on a broad range of modern Android versions.
- ABI coverage is focused on newer 64-bit devices.
Installation Guide
Open Settings on your Android device
Go to Security → Unknown sources (or Install unknown apps)
Enable "Allow from this source" for your browser or file manager
Open the downloaded APK file from your Downloads folder
Tap "Install" and wait for installation to complete
Launch the app from your home screen
Make sure to re-enable Unknown Sources restrictions after installation for security.
How to install this safely
How to verify the file you downloaded
Before you install anything, confirm the file is the one described here. On a computer, run shasum -a 256 your-download.apk (macOS or Linux) or certutil -hashfile your-download.apk SHA256 (Windows), then compare the output character-for-character with the SHA-256 on this page. If a single character differs, the file is not the build we recorded — delete it.
What the signing certificate proves
Every Android app is signed with a private key that only its developer holds. The fingerprint on this page is a hash of the matching public certificate, and it proves continuity rather than identity: it tells you a build came from whoever signed the earlier ones. Android enforces this at install time — if a package claiming to be com.phikal.regex is signed with a different key, the system will refuse to install it over your existing copy. A fingerprint that changes between releases is worth pausing on, because a repackaged app that has been modified by someone else cannot keep the original signature.
How to roll back to an earlier version
If the current release misbehaves, 1.3 is the last build before it. Android will not install an older version code over a newer one, so you must uninstall ReGeX first — which clears its local data unless you have a backup. Reinstall the older APK only if its signing fingerprint matches the build you already trust, and check the API range: an older release may target an Android version your device has moved past.
Why we list sources instead of hosting everything
The official store channel is almost always the right choice: it updates automatically and carries the publisher's own distribution guarantees. A direct APK is useful when a device has no store access, when a rollout has not reached your region, or when you need a specific version — and only when the publisher has authorized that copy. APKBrowse does not list pirated, cracked, or unauthorized rebuilds of ReGeX, and a listing is removed when the evidence for it stops holding up.
Get ReGeX
Every source we list for com.phikal.regex is legality-reviewed. Pirated or cracked builds are never offered.
Other sources
F-Droid listing
officialF-Droid builds this app from source and signs it. This is its official listing, with older builds and full release notes.
Source code
verified publisherThe upstream repository this build is compiled from.
We check legality and signature continuity, but device behaviour still varies. Install at your own discretion.
App Information
Security Verification
We record provenance; we do not run malware scans. Verify the hash yourself before installing.
SHA-256 Hash
36a6bde6bc0704f21dd57a8737a9054801e8b8cf74668be35003ce7aa7b989c8
Signing certificate
dff1778b6337b206398d017b4bb37c2fabbb90a332af5f711387890e69904169
Permissions Required
What each permission lets ReGeX do. A highlighted one is worth a second look — not necessarily wrong, just worth asking whether this app needs it.
Previous Versions
The signing certificate fingerprint for this release is on record, so a build that does not match it did not come from this publisher.
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