I use iCloud Keychain on macOS and iOS. Both operating systems include a rudimentary interface for managing passwords, and automatically store passwords entered in Safari. Keychain Access on macOS also allows to create secure notes on iCloud Keychain.
iCloud Keychain works great for me. Although, if I could change one thing, it would be to add a dedicated iOS app, instead of having to go to Settings > Safari > Passwords.
Its somewhat easier in iOS 11, there's a more dedicated area in settings. Also, in iOS 11, it provides usernames and passwords within apps, which is super convenient.
