Kudos! Desk workers are going to love this. You have kept the duration short and gamified it as well in the form of streaks. It should go viral.

A piece of feedback for the transition between two exercises. You may want to stop the bottom watch altogether during transition and - somewhere on top right -start a simple circular time animation 5..4..3 In the current form the transition looks bit confusing.

In any case, congrats again for the launch.