Spring Clean Photos allows you to clean up your iOS device's photo in a blink. On our iPhone or iPad, there's no quick way of deleting large amount of photos. The best you can do is to delete one by one using the photos app. Spring Clean Photos provides you a quick solution to achieve quick photo deletion.
You'll be able to filter photos and videos by date, you can then preview them to make sure you have a copy or backup somewhere, then they'll be deleted with a tap (with confirmation of course).
Spring Clean Photos definitely provides you the quickest way to free up your device's storage.
P.S. All photos and videos deleted will be able to recover in the "Recently Deleted" album in the iOS Photos app