Mask UI is a revision plugin of MaskShop based on pocketmine api 3.0.0, the author of this plugin has converted and updated to pocketmine based on api 5.0.0 (the latest version of pocketmine), if you want to see the original version of this plugin please visit
Next update I will revamp useless code, also I will make everything customizable (in your own language) everything will be controlled in config.yml, and several other important updates.
For the update wait for pocketmine 6 to be released, then I will update to 1.4
Instead of it giving them the effect once they buy it, Make it so if they put the mask on it gives them the effects. And If they take it off it removes the effects so its actually a mask and not just 'buying" the effects.
Of course, I will add this feature, but there is a problem in the ArmorInventory code to detect if a mob head item is used, which made me change it like that, but don't worry I will fix it in version 1.2-beta which will be released in about 1 month: )