Using this app, you can send donation to tribalfs on XDA for those who can't donate using PayPal. Donation will also unlock GMH's premium features on your particular device* as provided by tribalfs on XDA developers forum.

Galaxy Max Hz is created primarily for Samsung devices.
Compatibility with other brands is not guaranteed. Some features may not work.

Galaxy Max Hz features:
Refresh Rate Features
- Adjust minimum and maximum refresh rates
- Switch between adaptive and high(stationary) refresh rate mode
- Set Adaptive or High Refresh Rate Mode while on Power Saving Mode
(may not work on some devices with updated to OneUI4.0+ ; please test first)
- Adaptive refresh rate mod on devices with non-stock adaptive refresh rate mode
- Configure different refresh rate settings for every application

Screen Off Mods:
- Force lowest Hz on Screen Off /Always on Display (Ambient Display)
- Auto power saving mode while the screen is off
- Autosync Off while the screen is off
- Quick-doze Mod with adjustable maintenance window interval
- Auto SENSORS OFF while the screen is off (Experimental)

Others:
- Refresh Rate Monitor with quick settings toggle
- Resolution Switcher with quick settings toggle
- Tasker plugin support

Refresh rate-related features are only available to devices with multiple refresh rates.

*Premium is on a per-device basis

Please check FAQs in XDA for more info