I'm a huge fan of Pass. (https://www.passwordstore.org/). It's command line based but there are adaptations for various platforms. It works best in a UNIX-like environment, though.
Also by using GPG as an encryption mechanism it allows you to use your gpg-agent so you only have to authenticate when you log in to your computer.
Basically it relies on existing tools to solve existing problems (sync, encryption) and concentrates on the added value: listing, storage and retrieval of passwords.
A greatly useful application of the unix philosophy.