multi platform compatibility

Hi there,
Previous to 3 years ago, I used only Windows machines and happily used "The Journal" for my journaling - wonderful program, great support, terrific author. However, I am now a mac user and TheJournal author did not and does not plan to create a MacOS version. Though I've tried using it on my mac with Parallels, since it is only one of TWO programs I have to use this way, I find it cumbersome to work with. Since then I've been keeping an eye out for a multi-platform program that has even basic features inherent in TheJournal (tabs for different categories, dated journal entries as well as undated notebooks). This RedNotebook sounds promising, but my question is: If I install it on a windows machine and on my mac machine, can I keep the user files on a usb drive, and open up such files in either computer without any additional process?

thanks for your help.

Dawn D in NJ