Hey Timo,
Loved the app, and I purchased the PRO version. Before buying the Pro version everything was synchronizing well with my entries on my Android phone, however, stopped once I bought the app. I tried to log in to my account on Mac, however can't find where I can exit that previous free account and log in again with my Google account. Also, for some reason even synchronization worked fine for me and I initially logged into the same Google Account on both devices, on my Mac it still shows that I don't have PRO version so it can't sync.
Looking forward to hearing from you about that.
Cheers,
Vitalii