CleanUp is a terrific, free utility for iOS that has only one job -- it quickly deletes photos cluttering up your iDevice. You might wonder why you'd need such a thing. The answer is that Apple's method is a bit cumbersome. You can get a thumbnail view of your photos, and check off the ones you want to trash, but you don't see the photos full screen, so you might inadvertently delete pics you wanted to keep. Apple also provides an option to delete them from a larger view, but when you click on the trash icon you get a popup asking if you are sure you want to delete.
CleanUp changes all that. Launch the app, and you will see your most recent photo full screen. If you mark it for deletion, the app auto-scrolls to the next photo. If you want to not delete a photo, just swipe to the next one. But if you have large groups of photos grouped together CleanUp will get rid of them quickly. In my case, as an app reviewer, I have hundreds of screen shots. CleanUp made quick work of them. In one sitting I obliterated almost 300 photos with little effort. The process of deleting is really marking photos for deletion. You can tap the trash icon, or swipe up.When you are done you get the option to go ahead, or stop the process. If you leave the app and come back, you'll be just where you left off.
CleanUp is a real improvement in managing your photo files. I doubt I'll go back to Apple's method unless Apple streamlines it.
CleanUp requires iOS 8 and is optimized for the iPhone 5, 6 and 6 Plus. It's not a universal app.