https://monerodice.net/
Copied from FAQ:
Who owns and operates MoneroDice?
MoneroDice is owned and operated by Riccardo "fluffypony" Spagni, a Monero Core team member, as well as rznag, a developer living in beautiful Austria whose previous work includes the (subsequently sold) Kingcoiny altcoin exchange.
How do I know my Monero is safe with you?
Both of the site owners have a long history in cryptocurrency development, and own and operate multiple cryptocurrency related businesses. Until on-chain betting becomes feasible, perhaps with a Monero daughter-chain, sites like MoneroDice will have to exist. We hope that one of the site owners being a Monero core team member, coupled with the donation of 100% of the profits to Monero core development, makes playing on MoneroDice a good and reasonably safe idea.