SweepiusQuick answer: Sweepius finds every screenshot in your library, shows them oldest first with the total space they use, and lets you select all or pick a few. One tap and one iOS confirmation moves them to Recently Deleted.
Why oldest first
The screenshot of a boarding pass from two years ago is the easiest thing on your phone to let go of. Starting with the oldest means the first screen you see is almost all safe to clear, and you can stop scrolling when you reach the ones you still need.
How it differs from the Photos app
The Photos app already has a Screenshots album, and it’s free — see how to delete all screenshots on iPhone. Sweepius adds the size: you see exactly how many megabytes or gigabytes your screenshots take before you decide, and they sit next to your similar photos and large videos so you can clear everything in one visit.
Safe by default
Nothing is pre-selected on this screen, Favorites are never touched unless you choose them, and deleted screenshots stay in Recently Deleted for 30 days.