A free app for Android, by App Basic.
Collage Maker – Custom Photo Editor is an easy-to-use app to create custom collages. You can choose from a wide variety of layouts and styles, and the app will let you know how many photos you can use. Once you’re ready, you can choose from a wide variety of filters and effects to make your photos look even better.
Once you’re done editing, you can save the collages you create and share them with your friends. You can even use the built-in sharing tool to send the collages you create to your friends or family.
This app is free to use, so there are no hidden costs or fees to worry about.