If you're into donating cash to ecological charities in a somewhat roundabout fashion, try new Facebook app Plant Me.

It's another in a long line of slow burn resource management games - you pick a planet, sow seeds on it and nourish them into mighty trees - but here's the USP: for every five dollars (about three to four quid) you spend on virtual in-game cash, the publishers will plant one more tree in reality. Or so they tell us.

In-game cash, otherwise known as "Ozone Credits", can also be earned by accepting third party offers. Sign up for a free 14 day trial of LoveFilm, for instance, and you'll haul in 53 OC.

Feeling un-ecological? Don't worry - not everything in Plant Me costs Ozone Credits. You can get by perfectly well without.

Play Plant Me