Using fake money gambling application might be a good platform to curb gambling addiction but it would fail if there is no will power or determination to quit. Like you rightly pointed out mate that these application was mainly designed to improve gambling skills and experience. It might serve as a tool of increasing the addiction. After using the application to master some skills, most addicts might want to apply those skills to real gambling. Its just like advising a sex addict to curb his sexual drive by watching pornography.
Furthermore I don't actually see this as an Option.
There will be a difference when gambling with real money and games because even if the addicts are replaced with fake money and win, I still feel their pleasure will be different, they will not even feel happy at all and will actually prefer to gamble using ordinary money.
Addiction is something that is hard to fight and gambling with counterfeit money is definitely not the right answer.