I first learned of Street-Complete here and I really like it.
It’s satisfying to walk around, complete little tasks, and get prizes, scratching a similar itch to Pokemon Go.
Stuck waiting for someone? Add opening hours for a few local businesses.
Have a long walk ahead of you? See if you can add/check house addresses as fast as you can walk.
Want to walk off a few beers before heading home? Complete some tasks in the bar street.
Its a very constructive way to “be right” on the internet.
I’ll always upvote StreetComplete.