The best replacement for keychain is 1password.

The best alternatives to keychain are rated as following:
★★★★★  1password
★★★★  key chain
★★★  keychain
★★★  dashlane
★★  lastpass
★★  nsuserdefaults
★★  ssh-agent
★★  one password
★  keepass
  id holder
  mobile authenticator
  keyring
  roboform

Your alternative for keychain is not listed? Suggest!
Speaking about keychain, one probably shouldn't forget about wallet.

Other search terms related to keychain and their ratings are:
★★★★★ wallet
★★★★ card holder
You have in mind a companion for keychain and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of keychain in all years. Click on graph for more.
keychain
1password
key chain