Thanks for leaving your thoughts for us! I'll see about implementing an option for displaying more detailed roll information for those who want it.
The mysterious neutral/low/high indicators on the party menu give slightly more context on hover, but now that I think about it, I don't think there's any way to get that information to display for mobile players... I'll think on it to see if there's a way I can present the information more clearly in the limited space available in the layout.
To answer your question though, the neutral/low/high icon shows the "tension" of the relationship. It's a vague indicator of how much you butt heads with a given party member and operates independently of whether you are friends/enemies. For certain characters, it's possible to bicker (high tension) but still have high friendship, or dislike each other but behave civilly (low tension).