Steemit is built upon the block chain of Steem and just like it other apps can benefit from the same business model.
Here are 2 ideas for anyone fishing for them:
Create a Tinder-like app and have people earn money while voting :)
Swipe right to upvote. Get a #date, earn steem and pay the bill with it!
Create a Periscope-like or Twitch-like app and have the people watch your livestreems, upvote and earn steem!
These are just ideas and if anyone decides to go through with them, I won't hold them for anything...well, an upvote to this post maybe :)
Enjoy,
Anduweb