EMOM is the abbreviation for “Every Minute On the Minute”. It is a type of CrossFit workout. There is a given number of repetitions of an exercise (e.g. 5 burpees) and you have sixty seconds to complete the repetitions. If you finish earlier, rest. As soon as sixty seconds are over, you start the next exercise.
Depending on how many exercises you do, you can set the number of rounds with the app.
Talking tech, the app is a progressive web app. You can download it from the browser and add it to the home screen on your phone. The app does not require internet connection.