Here are my recommended apps. I'd post links but as a new user I'm not allowed to. Oh well.
This is the best painting/drawing app I've used so far. The ability to rotate the canvas on-the-fly while you're drawing is especially useful. The paint-blending is surprisingly realistic. It looks like painting with an actual brush. The interaction with the s-pen is perfect.
It's essentially a superior replacement for the default picture gallery app. A problem I had with android's photo gallery was that it included all the folders on my overfull sd-card, which made looking for pictures extremely frustrating. QuickPic lets you exclude folders (or even your entire sd-card). Also it's free and ADFREE.
A versatile video player. It can display subtitles.
If you're looking for a flash-card app, you can't go wrong here.
I'll update my list as needed.