Try checking and see where it leads you to. If it simply asks you to add the page to the home screen (should prompt), then it's legit.
It just adds a shortcut to the do menu and seems legitimate (balance is intact), but I don't understand how it still appears despite turning off all possible notifications in Chrome? I don't even know why I still use Chrome on my smartphone, maybe it's time to try Firefox.
@PawGo, does this mean that the owner has decided to introduce this feature on their site? Since you know what this is about, how can an ordinary user block such things?