According to the first post the official pools are Alpha, Beta and Delta.
In the UltraNote Wallet 1.0.4-beta there are Alpha, Beta and Gamma.
According to my knowledge - the Gamma pool is there probably by a mistake - pool does not work and site does not exist.
best is to look at
http://explorer.ultranote.org/#pools there you can allways find the official and supported community pools
My point is to let the developers know, that they shoul remove the pool from the wallet. Thanks