Higgs Domino Island is the official version of Higgs Domino game and contains great features for free, but it's not completely free. Most used features are paid and not everyone can pay this much for these features. Although the game is great but contains pay to win strategy in the game. It is available on the google play store https://play.google.com/store/games?hl=en&gl=US
Higgs Domino RP a modified version of Higgs Domino Island that contains all premium features for free. All modes are unlocked from start. The players receive unlimited coins which they can start using from start of the game without any issues.
https://higgs-dominorp.com Download here.