How to make a collage on iPhone?

I'm planning on making a collage for my team members with photos that I have collected year round from the teams social media accounts, I know how to make the collage on my iPhone. But how would I be able to make the collage larger and print it out for all 10 girls on the team?

If you have an app that lets you merge images to a collage, it would let you adjust the size. Printing from an iPhone is done to an Airprint enabled printer or an PC with connection enabled Or send the image to a PC or a Mac and print there.

I would just make the collage and then connect to PC and use windows explorer to cut/paste it then print from computer.