The hunt is on. Or it will be right after the main Google I/O keynote is over. If you're a registered attendee of the conference and you have some free time between sessions, the yearly location-based I/O treasure hunt will provide you with enough trivia and challenges to keep you entertained.

This year, you will be looking for Alex, the Android dog, who left a trail of NFC tags all over Moscone Center, starting with a booth on Floor 3. By answering questions and completing quests, you will unlock achievements and reveal some cool surprises that "you won't want to miss!"

Attendees who finish the quest will be able to claim a final prize as well, while supplies last. So if you're there, you may want to get started as soon as the app activates at the end of the first keynote. Good luck hunting!