I've had Swiftkey Keyboard on every device I've had. Lots of ways to customise it, bigger keys, having access to the numbers along the top row of the keyboard, but predictions are pretty spot on to. Give it access to your texts and it'll learn the way you type so predictions get better and better. Can also give it access to Bookface and your emails as well if you like.
Also Quickpic is the other one I have. When Google's Photo app changed I hated it, so switched over to it fully. Can create folders, move, and edit photos, and hide entire folders if you wish.