Using this app you can send a donation to tribalfs to get GMH premium features.
Galaxy Max Hz Donation — description
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.