You can share images by clicking the "Share" button on the bottom right-hand side of your photos. All sharing options appear when you tap the "Share" button!
Save to Camera Roll
Open History → Select a photo
Tap "Share" → "Save Image"
Share to Instagram/Snapchat
Open History → Select a photo
Tap "Share" → Choose Instagram or Snapchat
Text a Locket Photo
Open History → Select a photo
Tap "Share" → Choose Messages