Sync for reddit was a great 3rd party app for browsing reddit. Since 3rd party apps were ousted from reddit the dev repurposed his app for Lemmy. I've been using it today and so far it is fantastic. There are some ads, but at the moment it's the best Lemmy app on the market as far as UI goes imho.
yeah if I recall that was created by someone else with LJs blessing to use the sync name/code... so it may or may not be the same to how sync by LJ would be maintained... don't think anything ever came from that though but as I don't like IOS, I haven't really followed it :/