Hi Product Hunt, I'm the developer of Estos. It is a crisp, snappy and reliable Tabata timer for iPhone, and it went live on the App Store on 5 November.

Here is what each word rests on. Crisp: the digits read at a glance mid-set. Snappy: the classic Tabata (20 seconds of work, 10 of rest, eight times) is ready on first launch, so a workout starts with one tap. Reliable: cues keep playing with the phone locked, and your music keeps playing at its own volume under them.

For anything else you set prep, work, rest, reps, sets and the rest between sets. You can name each rep, a 3-2-1 cue warns before each switch, and a lock button blocks stray touches.

The free version runs every workout and saves 2 timers. Premium, $9.99 a year or $24.99 once, adds unlimited timers, sharing and a Home Screen widget. There are no ads and no account, and the App Store privacy label reads Data Not Collected. VoiceOver works, and the app comes in English and Ukrainian. I plan to add iCloud sync, Apple Health and more.

I trained with the app myself before release for weeks.

What does your current interval timer get wrong in the middle of a workout? I'll reply to every comment today.

App Store: https://apps.apple.com/app/id6817765756