Ideas for develop an tailored app for documentation and memories for troubled youths in institutions

Hi there.

I was hoping u could give some hints or good ideas to how to develop an app for documentation of the life of a troubled youth in an institution over a period. There will be several people working on this and would contain pictures, text/story and all other things relevant for the youth to remember the stay. There are several apps who could be used trough Teams and i would be grateful for tips on witch of them are best suited for this project. Most of the people who will be using this have little experience using those new apps, so "stupid and simple" are key words here. The finished project is meant to be printed in a book.

Thanks for tips in advance