I don't have an invite to Lift, but a lot of developers use TestFlight as a way to install applications over the web to testers. You sign up with TestFlight through a link the developer sends you, and you install a profile that lets your device install apps from that developer. You can then install the app from over the web. I've used several apps that way, it's a very handy little tool.
I don't have lift either, but I use http://www.hockeyapp.net/ to deploy provisional apps via a direct install to iOS