Friend Matrix is a Facebook app that allows Facebook users to create a collage with the pictures of the friends in which the best ones have the biggest pictures.

The app can be accessed from its Facebook fan page or directly on its website, facebook.com/friendmatrix and friendmatrix.co respectively.

Another application to edit photos is Photo Mania which can be found on this address: facebook.com/photomaniafx.

It allows people to upload a photo and to apply some automatic effects over it, for example black and white, sepia, and so on.