You and your friends will need to unlock the ability to see each others shots, which is done simply by sharing shots with one another. you can respond to a shot with a quick reaction gesture. You can view shots when you want to, and you can delete any that you send by swiping them away, and your friends will no longer be able to see them. You can annotate your images with text and drawings.
Slingshot is currently rolling out around the world, in countries like Australia, Malaysia, and India where the calendar has already flipped the page to June 10. We're expecting it to hit Europe and the United States at some point tomorrow, possibly as soon as midnight.