Flexible interval timers for sports training with dynamic duration control
About this app
Universal Timers is a flexible interval timer app designed for sports training, including specialized support for activities like apnea or climbing training. Create custom timer bundles with multiple blocks, each containing work and rest phases that can be repeated.
Key features: - Create custom timer bundles with named blocks - Configure work and rest durations independently - Set repetitions for entire blocks - Dynamic duration adjustment: Use delta fields to gradually increase or decrease work and rest times during a set - Minimum duration limits to prevent values from going negative - Clean, modern Material Design 3 interface - Dark mode support - Swipe to delete timer bundles - Save and manage multiple timer configurations
The delta feature is particularly useful for progressive training; for instance in apnea training you might focus on improving CO2 tolerance or O2 deprivation which some designated apps train by decreasing breathe-up times or increasing breath-hold times, respectively.
Licensed under GPL-2.0-only, by Michael Reuss.
What's New in v0.3.0
Imported from the F-Droid repository index.
Version history
Apr 29, 2026 · 9.8 MB · Android API 24–35 · code 9
Imported from the F-Droid repository index.
SHA-256 45ddf46794aa838464ab7c9bb4e00ecb3d2e2eb106c0eb5a999b120bb2535c94
Will it run on your device?
92%
- Runs on a broad range of modern Android versions.
- Multiple CPU architectures are covered.
- Aligned with the latest Android target SDK expectations.
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 io.github.hitchclimber.universaltimers 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
No earlier build is on record for Timer Bundle, so there is nothing to roll back to yet. When a second version is published, this section will explain how to move between them safely.
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 Timer Bundle, and a listing is removed when the evidence for it stops holding up.
Get Timer Bundle
Every source we list for io.github.hitchclimber.universaltimers 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
45ddf46794aa838464ab7c9bb4e00ecb3d2e2eb106c0eb5a999b120bb2535c94
Signing certificate
26bcef5fcf188add29dcde829ab28f3b3df2a6ea0b5c666da58522de03246329
Permissions Required
What each permission lets Timer Bundle do. A highlighted one is worth a second look — not necessarily wrong, just worth asking whether this app needs it.
Previous Versions
No earlier build is on record — this is the first release we have listed.
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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