Refresh Rate Changer 3.0 by RC Modz is a modified utility application designed to help Android users, particularly those with OnePlus devices, manually lock or overclock their screen's refresh rate to resolve scaling and performance issues. Overview and Purpose
Who it’s for Users with high-refresh displays who want lower power draw or to stabilize low-FPS apps/games; power users comfortable with sideloading and settings tweaks.
Caution
No. Refresh rate is a software setting, not a voltage overdrive. Running at 30Hz is actually less stressful on the display driver.
You're looking for information on a refresh rate changer, specifically the "30 by rc modz apk" from Google, and its relation to high-quality displays.
None, however, offer the dedicated “30Hz battery saver” focus of RC Modz.
Known limitations