This year, I've focused on improving the app's importing options. Previously, it only supported adding friends manually or via text.
Earlier in the year, I built a Google Calendar sync flow (using OAuth), and just recently, made a Chrome extension to import Facebook friends' birthdays.
The flow is—install the extension, pull Facebook birthdays, select friends, then import to birthdays.app (using an import code from the web app).
I'm unsure how many people still use Facebook, but suspect many mainly use it for birthdays nowadays (and may prefer text reminders instead).
I built this with a text-reminder-first mindset (over push notifications, calendar format, etc) because of the simplicity. I'd actually built my own makeshift solution a few years prior to building birthdays.app (using Google Sheets + Zapier SMS), and found the solution to work well.
To me, the text app feels like the social home of the phone (for real friends, at least), and it feels right for the birthday reminders to show up there.
Thanks for reading, and open to any thoughts around the Chrome extension or the birthday reminders in general :)