Microsoft Paint 3D on Windows devices provides a handy tool for creating, remodelling, manipulating and sharing 2D and 3D images. If you find your own personal Windows device does not already have it installed you can follow this link to get Paint 3D (available on the Windows 10 Creators Update).
Much more than the name might suggest, PicCollage is a free app which works on multiple platforms including iPads, Android, Windows and Amazon devices. Yes of course, as the name suggests, it can create collages of multiple images (and video clips) but it can do much more! And it has uses to support across the curriculum in different ways.