Hello,
You can sign up at
ios@openvpn.net but since we do not have a version in beta testing now, we cannot add you until we have a new version.
The last beta version was 1.2.9 which is currently live on the iTunes store.
We expect 3.0.x to enter beta sometime in the next couple of months, so we suggest holding off on asking to join beta until we actually have a new beta version finished.