1password on iOS/OSX. There was a big discount on both a while back and I jumped on it. Even today, I'd consider paying for it. I've tried all the open source options, none of them worked nearly as well as 1pwd.
1password is great. On OSX, I have one long, nice password and on iOS I can use Touch ID to open it (typing in that password on an iPhone was a pain). It syncs across devices over wifi, Dropbox, or iCloud.
There are versions for Windows and Android as well. I've used the Windows version a little bit and it's pretty much the same.
Initially the $50 was painful, but I've since happily paid for all the upgrades and for family members license' too - encouraging good password hygiene!
1password is vulnerable to hackers because they rely on third party storage via dropbox. I wouldn't trust my sensitive info with them.
Second, the data stored in dropbox is encrypted by a key that only you have. Dropbox has no way to see what is inside that bundle without your long password.