Apnoe Trainer runs breath-hold training tables on your watch. It times every hold and every breathing phase, signals each change by tone and vibration, and can record the session as an activity. Four training modes: - O2 table: the hold gets longer each cycle, the rest stays the same. - CO2 table: the hold stays the same, the rest gets shorter each cycle. - Combined: longer holds and shorter rests at the same time. - Simple: fixed hold and fixed rest. Each mode keeps its own settings. You set preparation time, hold and rest times, step sizes and the number of cycles (1 to 30) directly on the watch. With the defaults, the O2 table starts at 1:15 and adds 15 seconds per cycle up to 3:00 over 8 cycles. During a session the screen shows the phase, the remaining time, the cycle counter and your heart rate with a short trend line. A signal 3 seconds before each phase ends tells you what is coming; an optional countdown adds signals at 30, 20, 10 and 5 seconds. With "Open End" the final hold keeps running past its target until you press the button. Controls: the top button pauses and resumes, a long press on the bottom button skips the current phase, and the back button opens a menu to resume, save or discard. The touchscreen is disabled during a session, so a wet sleeve or a stray touch cannot interrupt a hold. Sessions can be recorded as Breathwork, Yoga or Other, or not recorded at all. Only "Other" gives you a lap table in Garmin Connect with time and heart rate per hold and per rest; Breathwork and Yoga show the phase chart but no laps. Every phase is stored as a lap with its target time, average and maximum heart rate, so each hold and each rest can be analysed on its own. The watch confirms every lap with a short vibration of its own, which an app cannot switch off. The activity file also holds the current phase for every second, plus longest hold, total hold time and cycles. After the last cycle a summary on the watch shows total hold time, longest hold, cycles and average heart rate. SpO2 (optional, off by default): when switched on, the app asks the watch for pulse-ox readings during the session, shows the latest value next to your heart rate and records it per second, plus the lowest value per lap. The watch decides when it takes a reading: in a test on a Venu 3 the value changed only about every four minutes. Treat it as a rough indication; it does not show how your saturation drops during a single hold. Languages: English and German. Safety: This app is for dry training only. Never practise breath-holding in or near water without a trained buddy, and never while driving or anywhere a blackout could hurt you. Stop if you feel dizzy or unwell. The app is a timer, not a medical device; heart rate and SpO2 values from the watch are not suitable for medical decisions.

1.0.4: Support for Forerunner 170 and Forerunner 170 Music. On the Forerunner 170, holding UP opens the menu and skips the current phase during a session; touch works as on the Venu. The "Done" label at the bottom of the number input is no longer cut off on 390 pixel displays. 1.0.3: Small correction to the new "Version" entry at the end of the settings menu; it now shows the version number only. Also new since 1.0.1: support for vívoactive 5, vívoactive 6 and Forerunner 55. On watches without a touchscreen the number input uses the UP and DOWN buttons, and the start screen says "Press START" and "Hold UP for menu". The start screen fits 390 and 208 pixel displays.