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.

Check Galaxy MaxHz github repository and/or XDA for its features and description. Galaxy Max Hz is created primarily for Samsung devices.
Compatibility with other brands is not guaranteed - some features may not work.

*Premium license is on a per-device basis

Please check FAQs in XDA for more info