Most information regarding Download and installation can be found on the wiki.
For your convenience here are helpful some direct links to helpful information:
Source Forge Buildbot downloads (these are bleeding edge and automatically built any time a change is made to the source)
Touch Input Guide
Known Issues
my TODO page
Please check the wiki known issues and bugs before posting a problem. If you prefer you may submit a bug ticket on source forge. Try to only post iOS specific bugs and issues here. If you aren't sure please test (if you can) with GemRB on another platform (try to use the same Buildbot version)
There is currently no stable release for iOS; only Buildbot incremental builds are available until next GemRB release.
For reference the old thread is here.