Hello Pascal,
Thank you for your feedback. Transferring files already is on my ToDo list, but with a low priority: You are actually the first one to ask for it.
But I'm getting asked for plotting support quite frequently, so I'll rather focus on that one. For the time being, you can copy/paste functions from/to Mail.app and send/receive them with your PC.
If you didn't write a 5-star review on the App Store yet, I'd be happy if you did (and feel free to recommend it to your friends and colleagues, too) :-)
Cheers
Daniel