This is my second purchase. The first one I used to leave in the shower after washing it so that it hung to dry with the unit dangling down. Having the unit still attached to the strap caused it to stay wet for a while due to water dropping down slowly; subsequently, the seal failed, and the unit was ruined.
So, in summary, great unit, works well, but take the unit completely off when letting the strap dry.
Expanding the minimal features mentioned in the header, the app allows for tracking, with a real time update of heart rate tracking. The app will log activities but that is it. No casting to other apps such as Strava, which would make this a 5 star review otherwise. The strap, however, is comfortable and adjustable and does the job of heart rate tracking as intended.