Coinrex is an on-line bitcoin gambling site. It is provably fair, and provides custom visual result validation. Users are also provided with an option to download all their gambling history in JSON format, which they can later validate via the validation page. The validation process is purely client based, which prevents the site operator from falsifying validation for some results.
Coinrex also provides a demo play mode in which the user can play for free, thus it can be used purely for recreational purposes. Among other of the Coinrex's features are no-register play, which is similar to on-chain gambling with bitcoin (by selecting payout, the bitcoins are returned to the sender's address).
Coinrex games are entirely web-based, i.e. no download or plugins such as flash is required, only HTML5 compatible browser. Coinrex web site is also optimized for mobile devices.