I’ve seen AEBet as a first gambling aepp, but their house profit is very high 4% (max. roll is 96 of 100) and it looks like a privately driven project.
I’d be glad to see on Aeternity something similiar like Etheroll on ETH.
Its one of the oldest and still successful Dapps.
It had a community funding for the bankroll, participation of the community (btw. holder of their DICE token traded on some exchanges) in very low house profit of only 1% and open source code.
The community of moren than 1600 holders (!) built some nice analytic tools around it and payout is quarterly (which is not always guarantied of course 
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For my understanding AE is idealy suited with its inbuilt oracles to built such a community driven gambling aepp and its fast transactions per second (compared to ETH).
The source code of Etheroll could be a blueprint for such an aepp.
Such an open source aepp would bring some fun into the use case of AE and could suit as great public testing case for several crucial parts of the technology!
Unfortunately I’m not a blockchain developer and can only help with the impulse of the idea and as a funding participant.
I’d be happy to hear if a group wants to start it.
I could bring in a number of people from Etheroll who would like to fund and support that idea, because it is sucessful and fun on ETH and could be much more here at AE.