Photo viewer for Mac that can rotate (and save) pics while browsing folders
So if you only want to spend $2 for such an app, you definitely will be disappointed in every direction you will take a look at.

Regarding my most famous and favourite graphics manipulation and imaging software "Graphicconverter", which can do everything you want and described, you would pay 35€. But if you want to, you can try it out. 

http://www.lemkesoft.de/en/products/