Is it specific areas that take time to load or is it constant? On my phone it works fine but I haven't been able to test it on any other different devices.
Not a lot I can suggest if it happens in every location. The only thing that really changes in places like the mall are the BG images and updating the location buttons. Neither is heavy enough where it should cause a noticeable hang.
The game is also pretty small so probably isn't a memory issue. Only thing I can think is that renpy and your device are not getting along very well and causing the issue.