Following the initial release for Beast Timer and a post to Reddit's r/Android, it seems like Progression is a favorite among Redditors.
In the name of market research, I downloaded it and found that it does have some very good features. The biggest three that are useful but were not present in Beast Timer are: workout summary with lots of stats, exercise images and instructions, and popular workouts.
That is no longer the case. Version 1.20 of Beast Timer now has those three features and many more improvements. One of them is the ability to advance to the next set without reaching for your phone. You can configure Beast Timer to advance to the next set through a headset command, such as "Previous Track", or "Pause". This way you can simply hit a button on your wired/bluetooth headset to start the timer, receive an optional audio and/or vibration cue when it's time for your next set, and go about your workout with one less thing to worry about.