Needlessly gaudy, flashy UI (with sound...?) which I'm guessing is designed to make one feel like they're using some state-of-the-art software in a techy TV show. Gave me a headache after 1 minute of use, and only allows images to be stitched side-by-side (at least in the free version - I'm guessing the $2 extension pack permits further utility, but it was pretty difficult to ascertain what that purchase provides). For such limited utility I'll stick with Union.

This app does one thing EXTREMELY well, and it’s something that I have not found any other app to be capable of doing. What it does is combine any number of photos (well, a lot of photos but maybe not a million photos) together horizontally or vertically into one .png image. By comparison, collage maker apps allow you to join a fixed number of photos together (maybe two or four or so), but they do not have the ability to add and add and add and continue to add photos in a row or column. This ability is extremely useful if you are making a storyboard or something similar. I used it to concatenate a number of street view photos from Google Maps to make a turn-by-turn guide for getting from Point A to Point B for my trip to Europe. I can then access that one photo off-line when I get there and visually see how to get where I want to go.

I was searching for an app to concatenate several images into a single image, edge to edge. Tunacan popped up in my search so I tried it out. It did exactly what I hoped it would do. The result was perfect. I’m very happy with this tool.

Can't overlap images. Can't rotate one image slightly to manually align. I just spent $2 to tell the developer what he/she already knows.