(SECUSO) Supports circuit training sessions and helps achieve training goals.
About this app
Privacy Friendly Interval Timer supports the user during his/her circuit training session and helps him achieve his/her training goals. In order to support the user during his training, the app provides stopwatches, which can be configured according to the user’s own training and resting phases. In addition, the app reminds the user of previously defined training sessions via a notification.
To check the user’s goals and to recognize training progress, the app offers the possibility to retrieve statistics about the training times and the calories burned in a daily, weekly or monthly overview.
This app is part of the Privacy Friendly Apps group developed by the research group SECUSO at Karlsruhe Institute of Technology.
How does Privacy Friendly Interval Timer differ from other similar apps?
1) Minimal permissions Privacy Friendly Internval Timer requires the persmission "Run at startup" to automatically restart the motivation notifications when the phone reboots.
For comparison: The Top Ten similar apps from the Google Play Store, require an average of 9,1 permissions (September 2017). These are for instance the permission to access accounts, permissions to access, modify or delete storage and access to networks or the internet.
2) No advertisement Moreover, Privacy Friendly Ludo distinguishes from many other applications in the way that it completely relinquishes advertisements. Advertisement might track a user's actions. It could also shorten battery life or use mobile data.
Feel free to contact us via: Bluesky - @secusoresearch.bsky.social https://bsky.app/profile/secusoresearch.bsky.social Mastodon - @SECUSO_Research@bawü.social https://xn--baw-joa.social/@SECUSO_Research/ Job opening - https://secuso.aifb.kit.edu/english/Job_Offers.php
Licensed under GPL-3.0-or-later, by SECUSO - Security Usability Society.
What's New in v1.3.3
Imported from the F-Droid repository index.
Version history
Jul 21, 2025 · 7.5 MB · Android API 21–34 · code 100
Imported from the F-Droid repository index.
SHA-256 df8b55fbf5cd2e31a2cba93d641f4f8bd7988c4ea9cd2cf7c2d0317b945da847
Oct 8, 2023 · 4.7 MB · Android API 21–33 · code 5
Imported from the F-Droid repository index.
SHA-256 04bc206cf3013cf4b20b63b0ef5bd855bd8433e4ee8f7e6c72dda70f66cca4a0
May 9, 2020 · 2.9 MB · Android API 21–29 · code 4
Imported from the F-Droid repository index.
SHA-256 353c6a7474497d90d5d17777f85aa56142f1775351d744e00eec9b02bb8cfb91
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 org.secuso.privacyfriendlyintervaltimer 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 Interval Timer (Privacy Friendly) 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 Interval Timer (Privacy Friendly), and a listing is removed when the evidence for it stops holding up.
Get Interval Timer (Privacy Friendly)
Every source we list for org.secuso.privacyfriendlyintervaltimer 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
df8b55fbf5cd2e31a2cba93d641f4f8bd7988c4ea9cd2cf7c2d0317b945da847
Signing certificate
617e02c61b827ee31abe2979187c2997b624d00f274209495f53703ddd4357e0
Permissions Required
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.
Report a problem with this listing
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