I would love an option to turn off notifications when friends complete the Daily Challenge.
If you have a lot of active friends, you end up getting these notifications all the time, and they can get pretty annoying. I know other people who feel the same way.
I don't think the notifications should be removed completely, but it would be great to have a setting to turn them off if you don't want to see them. That way, people who like them can keep them enabled, while everyone else can disable them.