Apps you don't. You can move small pieces of apps to the card, but links to the pieces stay in internal storage, so you don't save much, if any, space.
Any other files? Any file manager.
MyFiles is good, so is
Total Commander. So is
ES File Explorer. Pick your favorite one.
Or you can move them to your PC, then move them back to the SD card. (Then you have a full backup on the PC.)