Beware 3.29.3 with iOS.
I was able to sync logs from the RuuviTag with 3.28.13 on iOS but after upgrading to 3.29.3 the syncing stopped working. Android syncing still worked, with both 3.28.13 and 3.29.3.
Downgrading to 3.28.13 with iOS resolved the syncing problem. There are, however, some gaps in the logs, too. I have no idea why.