I did a poll and nearly 30% of the people who voted said they used Sync! It's stayed around that percent the whole time too!
EDIT: Here is the poll I forgot to put this here like five times lol https://strawpoll.com/wby5A21R1yA
I tried Jerboa and Connect after the Red exodus. They were both alright, but it was still too different from the RIF app that I used on Red. Sync really closed the gap, and feels almost indistinguishable from RIF now.