I was enthusiastic about this being able to replace Roundcube/Gmail (what I currently use), but it's rather ugly (no offense to the author.)

If nobody else is going to, I may start work on some better styles for it. Also, I'm not really sure why there are two panels and profile pictures; neither gmail nor Roundcube nor Outlook do this. (Gmail and Outlook do put profile pictures to the side of the email itself when opened, however.)