Intertakt

In a glider, the instrument that matters never shows a screen: it speaks in beeps - a rising chirp when the air lifts you, a low tone when it lets you go. The pilot's eyes stay outside the cockpit. Intertakt brings that arrangement to interval training. Voice cues and countdown beeps ride over your own playlist, each channel at its own volume, so HIIT and Tabata sessions run with the screen off and the phone face-down. An incoming call doesn't reset the round: the session survives calls and app switches and resumes from the exact second it stopped. The free tier is unlimited - 0 ads, unlimited sessions, 0 accounts - and Premium is a one-time purchase, never a subscription. Live on Google Play.