The Treezer iPhone app enables its users to demonstrate their green consciousness by taking a very direct approach. The app is available in the iTunes Store, and to take part in the campaign, users simply need an iPhone with a camera and an Internet connection. The task is to take a picture, virtually place a tree in the picture and then share it on Facebook. For every posted picture, a real tree is later planted. Participation in this project is thus very easy and has resulted in the planting of thousands of trees.