From the official Agile Bits blog:
1Password 4 for Android arrives on Tuesday, June 10. It is an entirely new and full-featured app, built for both phones and tablets!
It is also an experiment. All new features will be unlocked and free for everyone to use through August 1, 2014. After that, 1Password 4 for Android will go into a reader mode, and all features can be unlocked for an in-app purchase.