Samsung released a nifty app that lets you tune your screen resolution & FPS rate for all your games or just specific games.  The app is called Game Tuner and is dead simple to use, you just need a supported device. But I guess Samsung will be bringing support for older Samsung devices in the future.

Supported devices: Galaxy S7, S7 edge, Note 7, Note 5, Note 4, Note Edge, S6 Edge +, S6 Edge, S6, S6 Active, S5 (SM-G906S/K/L only), Tab S2, Tab S (8.4″, 10.5″), Note Pro.

You can use one of the preset modes applied to all games or you can manage them individually by title.