1Password was one of the first apps to update on my phone the moment I installed iOS 8. I looked at the release notes in the app store and nice words like extension and TouchID made me say in my mind "YES! Finally!".
I like 1Password; although I have no idea of what my passwords might be on any of the services that I use; the fact that 1Password integrates so well with Mac and no iPhone is just a joy to use.
You create one master password for 1Password and you create some crazy password without realizing that you will have to enter that every single time you want to log into a service on your phone. It was a pain, but with TouchID and extension you don't have to worry about it anymore.
So far all the updates to 1Password for iOS 8 have been awesome, minus the iCloud sync part that requires Yosemite; well a few more days I believe.
Where 1Password fails is the way TouchID is integrated. Apparently TouchID will work after entering the master password once until the set time (you have to set this in settings) and the maximum time available is 1 hour. Why?
I fail to understand why wouldn't 1Password follow the same integration pattern as the Apple's app store? Use TouchID every single time, unless the phone has been restarted/reset.
It still is a pain to type in your crazy long master password on 1Password with or without extension.