Circulus — Training Timer

Matthias Eitner

Contains ads

About this app

Build your routine from activities, rests, rounds and stations. Run it on your own or together on the same countdown. No account, no sign-up.

WHY CIRCULUS EXISTS
My boxing group worked through a lot of timer apps. None of them won us over: either features were missing, or the basics sat behind a paywall. So I built the app we should have had.
It was made for us — and built so that it works for anyone who knows the same problem.

FOR YOU
• Create and edit routines
• Add activities, rests, rounds and stations with parallel lanes
• Run it in overview mode (shows every parallel lane at once) or in station mode (you pick one lane per station)
• Write an introduction, add a Spotify or Apple Music link as a suggested soundtrack

WITH YOUR PEOPLE
• Send a routine as a link through any messenger — or as a file, and even the clips travel with it
• Group mode: set a start time, the others scan the QR code, every device counts the same countdown
• No account, no sign-up, no email invitations

FOR YOUR COMMUNITY
• Record your own clips and use them in activities
• Keep a profile, pass your routines on
• Link a YouTube video in the introduction

YOUR DATA STAYS ON YOUR PHONE
Circulus has no server. Routines, profile and settings live on your device and nowhere else — there is nothing to sync, because there is nowhere to sync to. Group mode works without any connection between devices either: the QR code shares the start time, and every device handles the rest on its own.
Routines leave your phone only when you deliberately share them.

FREE. COMPLETE.
Every feature is included. There is no pro version, no subscription, no locked switches — that was the reason to build this app in the first place.
Ads carry the running costs. They appear in the library and after a workout — never during a workout, never while sharing.

THE CLIPS THAT COME WITH IT
The five exercise clips Circulus ships with were generated with AI. They are there so the app is not empty on day one — the clips that matter, you record yourself.
The spoken cues are generated with AI as well.

QUESTIONS, IDEAS, BUGS
Write to me: [e-mail] — or on X at @just_mazen.

What’s new

Circulus is here! Build your own training routines, run them and share them with friends – as a link or a file. Or train together: one QR code puts every phone in the room on the same countdown. Completely free.