There probably won't be an iPhone app for a while since Apple has pretty strict requirements for the App Store, also they don't allow cross compiling. I'm working on an Android app though.
I'm very interested about this problem with the save data on my website. I guess it only happens in Safari? Can you see if it works in other browsers?
Can you also see if it saves correctly when you use this link? https://app-polytrack.kodub.com/0.5.0/