The challenge app for people who actually show up.
Pick something you wouldn't do alone. Name the Bond, set how long it runs, agree on a reward for whoever makes it to the end, and send the invite code. Takes a few minutes.
After that, everyone posts. Photo, video, caption. The feed updates in real time. You can see who's keeping up and who's gone quiet.
There's a progress bar counting the days and a ranking of who's posted the most. Nothing complicated. Just a clear picture of who's following through on what they said they'd do.
Free on the App Store.