Additionally their support is really good. They added a feature on iOS version (and Android I assume) which copies the TOTP when you use codebook to auto fill a login. However it cleared the clipboard when the TOTP code expired which was sometimes too soon - I suggested they add a buffer of ~15-30 sec which most TOTP validators allow, giving the user a bit more leeway in pasting it. They added it in the next version.
Some cons though: They do lack Linux support. Syncing is manual (I think they mentioned the next big update will make it more automatic), and there aren’t any family/team sharing capabilities. For these reasons I would really only recommend it for tech-savvy individual use. I’ve recommended it to a few colleagues and they have had great experiences and continue to use it for several years now.