The Treezer iPhone app is at the centre of a campaign that allows people to directly show their environmental awareness. The app invites users to take a photo and to virtually place a tree in it before uploading it to Facebook. A real tree is then planted for every posted picture. This easy way to participate in the project has resulted in the planting of thousands of trees. The commissioning foundation, Stiftung Unternehmen Wald, has thus managed to raise public awareness for their cause and the “tree sponsors” are presented with each Facebook post.