The iPics2Go app can automatically crop for 3x5" prints when selected. The iPics2Go also comes with a 35mm film carrier, which can take a 4-5 frame strip of negatives, or a mounted 35mm slide.

Note that you can also scan positive (slide) 35mm film, but unfortunately there's no way to scan mounted slides. You'll need to put a pair of AA batteries in the scanner before starting.