Latest official realease is always available on Pitlab’s web site:

http://www.pitlab.com/fpv-system/download.html

TEST or BETA version is not an official release, and  may have some bugs and new functions not working stable yet.

ALL BETA TESTERS USE THIS VERSION ON THEIR OWN RISK.

TEST and BETA versions are  intended for users who want to participate in open tests and want to try new functions  in different  environment (airplane, rc/video  equippment etc).  This helps to make official release as stable as possible and working in all configurations and with many third party equipment.

Please report any issues and bugs on RC Group forum:

RC Groups Pitlab & Zbig thread