Here are the statistics for app downloads:
Here u can see the trade activity:
It is the arbitrator address which receives the create offer fee (0.0003) and the take offer fee (0.0008 btc).
Not very easy to get out the numbers but the numbers for the last 2 versions are with today (25.4.):
249 create offer payments in total (version 0.4.2 and 0.4.3)
54 take offer fee payments in total (version 0.4.2 and 0.4.3)