Yea, our current solution, as Roustem mentioned, sort of recreates the Dropbox app on Mac. We replicate the entire keychain file on the device, then perform syn

Yea, our current solution, as Roustem mentioned, sort of recreates the Dropbox app on Mac. We replicate the entire keychain file on the device, then perform syncing to keep both up to date. Our newer OPVault format uses band files, each band file is named after the first character in each item's UUID, which means we have far fewer files than AgileKeychain (individual files for each item). They both have their pitfalls, but initial sync with OPVault is infinitely faster as number of items increase. We did a ton of testing when we switched to the new Dropbox API and we had AgileKeychain's with thousands of items in them. They took awhile to sync. The same number of items in OPVault was nearly instant, at least with regard to the replication portion. Sync still took a little while due to the encryption and decryption that had to happen. Sync with 3rd party sync services have always been quite difficult for us. Especially from a troubleshooting standpoint. It's hard to replicate certain issues because the data is incredibly sensitive for users so we can't "get" the data and instead have to try to duplicate the issue with limited information. Every day is certainly a unique challenge :) Kyle AgileBits