I've made a widget for unread reddit messages.
Set the predefined action to open URL: https://www.reddit.com/message/unread/
and on long press to open URL: https://www.reddit.com if you want an option to go to your front page too
-- You need to go to https://www.reddit.com/prefs/feeds/ while signed in, copy the link from the JSON button next to Unread Messages and paste it into the script below.
set jsonurl to "YOUR URL" tell application "JSON Helper" set UnreadFull to fetch JSON from jsonurl set unreadcount to dist of |data| of UnreadFull end tell if unreadcount is 0 then set unreadcount to " " end if return unreadcount