My favorite feature: The Team-Mode, where you and friends can battle it out. Great when hanging around with a bigger group of friends, you can split up for a set amount of time and see, who gets the most points.
I am not affiliated with the app, but really enjoy it and thought that you guys might like it as well. Have a nice day!
Had to check it out on Google Play: https://play.google.com/store/apps/details?id=de.westnordost.streetcomplete
That looks pretty cool! Love that you can play it like a game as a team. I need to try this out