While not new to the latest Apple software update for iPad and iPhone, this was new to me. You can do some very basic editing of pictures within the Photos app. To enlarge any of the pictures below, simply click on them.
After taking a picture (or a screenshot, as in the example below), view the picture full screen in the Photos app. When editing photos, the original will not be saved, so you may want to make sure you have a couple copies of the original.
Tap the picture to bring up the toolbar at the top. Tap Edit.
At the bottom, you'll notice four tools: Rotate, Enhance, Red-Eye and Crop.
Rotate and Red-Eye are pretty self explanatory. Enhance will automatically make color adjustments for you.
Click Crop. A grid will be placed over the picture.
To crop the picture, grab the grid from the corners or edges and drag in to surround the area you wish to keep. Use Constrain at the bottom to keep the dimensions of the crop grid set. If using Constrain, drag the picture to fit the grid. When you are finished, tap Crop in the top right corner.
A preview of your cropped picture will be displayed. If you would like to crop again, tap Crop at the bottom. If you wish to leave your picture edited, tap Cancel. Click Save to keep the cropped version. Remember, your original picture will not be saved.
Your edited picture will replace the original.
If you are sending the picture to Dropbox, you'll need to take another screenshot of the edited photo. For some reason, Dropbox is not reading the edited photo, only the original.