Photo FX - Editor,Effects,Art has a lot of editing tricks and cool collage layouts, but it's heavy on the advertisements. They'll hit you often, coming at you whenever you finish up a photo or drop one into the collage. Still, the number of features in this app may be worth putting up with annoyances.
In addition to letting you put your photos into one of a few dozen collage layouts, Photo FX lets you do all sorts of edits to any photo you want. You can add color, touch up the lighting or blemishes, and even crop your photos -- though this isn't as customizable as it is in other apps. There are lots of filters and borders for your photos, as well. You can edit each photo in a collage, individually, so you don't have to settle for one design style when you're making your collage. PhotoFX offers plenty of borders for your collage, but they are all relatively basic squares, which gets a little boring after a while. The app is packed with annoying pop-up ads that will show up often when you're using the app. That, combined with a fairly boring layout makes the app tough on the eyes. The app isn't terribly difficult to use, though. In fact, it's easy for beginners to jump right in and start editing photos, as long as they're careful not to tap any ads.
Though some of the apps that rival PhotoFX in features are ad-free, this free editor has a lot to offer your photos. If you don't mind dealing with ads, you should try it out.