Interesting. I wouldnt use it to seriously store funds, as any chrome extension can potentially be compromised if someone happens to gain the ability to change the application somehow, and its always a good idea to store coins in a hardware wallet (unless youre okay with losing all the funds you have on a desktop wallet).
One popular gambling dApp Ive seen is
Dice2Win. Theyre a dice-oriented gambling site that some people have said to be decent.