Well, The app i use for screenshots is called "Screenshot" and i can say that personally
is the best screenshot app there is, and for rotating pics just use the app "QuickPic" which serves me as replacement for the stock Gallery app which sucks. QuickPic lets you rotate the pics, aswell with options to share with social apps. although you need to have Softkeys, or Button savior installed to access the menu button. Is not a hard process at all and the best of all is that both apps are free.