Gallery and phpBB
The Gallery integration module for phpBB 2 can be downloaded here - you need to create a user account before the download:
This module can be easily installed with the Easy MOD installer for phpBB.
Please mind that the application integration can be a difficult and a time consuming procedure.
SiteGround.com provides it as a paid service.
If you need assistance with the phpBB-Gallery integration, please post a ticket in Exclusive Professional Services -> Application Integration.