Hi! Sorry for this experience, I am aware of a somewhat poor performance on the phones. I put a significant effort into phones support about a year ago, but never revisited it since then, while keeping adding new content.
Tell me please, do I get it correctly that the problem only appears after playing for some time? If so, how long would you say it takes, approximately, for the freezes to start? Also, if you don't mind sharing your phone specs, that info would be helpful too.