This is a quick tip that comes in handy if you take pictures with your iPhone, iPad, or iPod Touch. To quickly jump over to your Camera Roll without leaving the Camera App, simply tap on the thumbnail icon in the lower-left of the screen that displays the last photo or video you took.
This will give you immediate access to the photos in your Camera Roll. Hit the Done button in the top-right to jump back over to the Camera App. Pretty simple.
3D Touch Bonus Tip! – If you 3D Touch on the thumbnail instead of tapping, you can take a quick Peek at your Camera Roll. While leaving your finger on the screen, slide to the right to view your photos from most recent to oldest. Pressing more firmly on the screen will cause the photos to Pop open so you can view them more fully.