Virtual pet or Zen garden

You would have to work out and fulfill active challenges each day to earn points to build a garden and keep it alive or same idea but with a virtual pet. Daily active challenges/earn ponts + motivation/keep plants and or animals alive = meeting activity goals. Activities completed earn points or Nex cash

and you can spend them on different plants for the garden or food for your pet. But if you are gone for to long, things start withering away until you have to build from new.