Why use a separate app to edit your photos? The built-in Photos app offers a variety of basic features for sharing and editing photos that may just handle most usage cases without needing to launch a separate app to make rudimentary changes to photos. This is how to use the Photos app!
Launch the app and choose one of the photos that you want to view and/or edit. You are first presented with the Share arrow for posting to various social networks, sending it to people, or other options. The Play arrow will start playing a slideshow of photos in the album the current photo is in. The AirPlay icon will send the photo to an Apple TV on the network. The trash can icon will delete the photo. Don’t expect this to look the same in iOS 7, what with the death of skeumorphism and all.
The real fun starts with the Edit button in the upper right corner. The rotate button will change the orientation of the photo, which is handy if photos have come out sideways. It rotates photos in a counter-clockwise 90-degree turn with each press.
The wand icon will turn on auto-enhance, which adjusts light and color levels in the photo automatically to try and make it look better. Tap the icon again to toggle it, and tap Save in the upper-right corner to save the change. The red circle with a line through it is the red-eye removal tool. Tap on a photo with red-eye and it will be removed if the app detects red-eye. Finally, the crop icon will allow for photos to be cropped. This is grat for making precise changes when wnating to share a photo to Instagram, or creating a new Twitter avatar. Use the Constrain option to force the cropping section to a certain ratio.
The forthcoming iOS 7 update will add new features like filters to the existing set along with a new design, so be prepared to do even more with photos, from Photos!