Thunder Page Speed Optimizer

I hate giving poor reviews, but this app simply isn't working at all. At first I only saw a blank screen when opening the app. Ok, the app support responded quite fast to solve the issue and confirmed it was a bug on their/Shopifys side. But then the optimization page just freezed and nothing happened. I didn't see any kind of progress on the dashboard or in the history tab. And now I'm back to seeing the blank screen. Very frustrating and what's even worse, the app support disappeared and is not replying to my emails anymore.