Oh wow, that's really cool! The popularization of cognitive science and psychology has resulted in some really great stuff, can't wait to see what this is! Let's keep reading the comment.
>- to learn something new
Awesome! I love learning new things! I bet this app/whatever has a lot of cool programmed learning tricks to make this great like spaced repetition or elaborative rehearsal. This sounds really cool.
>- to exercise
That's awesome too! Exercise is scientifically strongly linked to a variety of good outcomes for mental and physical health, so it should really be in an app like this.
>- to do an act of kindness
That's pretty advanced! The research about how gift-giving and similarly altruistic behavior is useful isn't as popular as the exercise research, this must be a really cool app with a lot of great empirically-minded ways to "push" you into having better habits!
>- to meditate
....oh. I guess it's just a new age/woowoo thing. Time to move on I guess. That's really disappointing.
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Really hope you remove meditation; hokey religions have no place in the modern nudge-engineered world.