I know this falls more into the Online Logbook category, but a simple Flight Review or Instrument Proficiency check reminder either through email or text would be a cool feature.
Dunno if this will help you, but I set up my calendar in Gmail (Outlook will do the same) to remind me to check my electronic log book to verify my currency dates. More informational for me since I am determined to touch a cloud once a month, but my night currency tends to lapse.
I set up my BFR for of course 2 year reminders (one month before they are due) as the same for my medical.
My aircraft maintenance such as .411 .413 and annual same deal, reminder one month before.