Syncing is a Notoriously Difficult Problem to Solve

And it’s also free as part of the recently released Vesper 2.0:

There is no charge. No subscription. You just create an account using your email address as your identity and it works. I’m as suspicious of a free lunch as the next guy — probably more so, in fact. But Vesper Sync is not a free lunch, because Vesper is not a free app. Sync should be a feature, not something you have to pay extra for.