Good news if you're a school who uses Pic Collage (as you should). There's now an education version which gets rid of those annoying game ads that pop up everytime you finish a collage. No account is needed, and there are no social media links to distract the little darlings while they are creating. One of the best uses we found in the classroom is the ability to make title pages for our books in Book Creator (app smashing).
This app is perfect for iPad classrooms and is one of the apps on our core app list. Basically it's pic collage with the added bonus of being safe and secure. The app is $2.99, but hopefully by now you're using Apple VPP which means it's half price if you buy 20.