Photoful!

Photoful! is a photo editing tool that lets you combine different pictures in one in a really easy way.

Choose different frames, add space between them, adjust their size, etc. You can also add text in different sizes, colors and fonts and choose the background color. Once you've combined the photos, save the collage as JPG, PNG, TIFF, GIF or BMP.

In short, Photoful! is useful if you want to combine two or more pictures in one. If you want to do something else, you'll need another app.