I'm using only the Google signin function for a client's website, and it does exactly as it says. Usually, when reviews say "excellent support", I think: if the extension was any good, support wouldn't be needed. But. For this extension I needed a couple modifications, so I asked the developer, Alex if he could help me out (and immediately refrased my idea of the need for support in relation to the quality of the extension). Alex helped me with these modifications and that was a very pleasant experience. People, this guy IS support. Asks all the right questions, is friendly and helpful and comes up with a useful solution. And thanks to him, my client now thinks I can perform magic.