The two killer features I'm looking for from a mobile app are easy sign up including key storage during sign up with a prompt to print/save/keep outside the app the master pasword.

For sign up not on the app but via other systems, I'd like to see a QR method of transferring the keys to Keychain storage, something really easy.

As a final request I'd like to see the mobile app able to sign requests from the browser on mobile and even on other devices, probably via photographing a QR code.

The biggest drive in Hive should be UI and ease of use for non crypto people.