PhotoAffix is in beta, it's still being developed. It's also open source! https://github.com/afollestad/photo-affix
PhotoAffix allows you to combine photos together, in vertical or horizontal orientation, to create one single image. A common use case for this is to create multiple device art screenshots of an app, and combine them together to make a showcase image.
Icon by Eduardo Pratti. Play Store feature graphic by RB Designs. Thank you for the graphics guys!
Please don't rate this app badly because features are missing or it doesn't work. It's open source – please report issues to me, and contribute if you can.