For starters, if you have one big photo you want as the background, you cant set it as the background. Then, when you blow it up to be the background, and youre working with smaller photos, and you accidentally click the back photo, the back photo is brought to the front and you have to restart the entire collage because theres no way to send the big photo to the back. And every photo has this stupid white border that I want gone but I cant get rid of. Then when shrinking or making photos bigger, it all depends on your finger size. Theres no scale to slide. And it also rotates while you scale, which is very annoying. Also, you can only do 4 photos per collage, and if you want more you have to pay. But I have to keep this app because I cant find any other free app that lets me put photos on top of photos.