They will pay money for doing various tasks, but where will this money come from exactly 
That's excellent question.
Advertisers will pay for that like they do on faucets nowadays or any other "pay-per-smth" sites. For simple tasks like making selfie with your cat you will get small amount of Cron$, but if you go to paid place and check in there, you will get much more.
You can open you mobile app and see places on map. You can choose which one pay more or which one suites more to your needs.
Also, Cron$ will be backed by CRYPTonFly shop goods, which you can buy online.