Coinprism is a Colored Coins web wallet. Coinprism is similar to other web wallets, except you can store, issue, send and receive Colored Coins and not only normal Bitcoins.
Colored coins allow you to store assets on the Bitcoin blockchain. There are many interesting applications to colored coin. You could have an IPO on the blockchain by issuing shares as a colored coins, and send them to your shareholders. The shares can then be traded almost instantaneously and for free through the Bitcoin blockchain. You could have smart properties represented by colored coins. You could store your house on the blockchain by issuing a single coin, then the ownership of the house can be transferred with a simple Bitcoin transaction.