Camera Genius is Nr. 1 in Top best photo editing apps. Give it a try.
Find Camera Genius on App Store & download it.
After installing Camera Genius, take a picture or import from your library an existing one and start editing it.
You can use a special filter
Or make some color, contrast and other adjustments
Or make an interesting collage
Or simply add a frame to your image.
The creator of this guide has not included tools