Is there a free app to delete photos by swiping?

Use your default Photos app search. Type years or keywords like “2020”, “food”, “concert”, “work”. Delete in chunks.

Example:
• Search “WhatsApp” or “Messenger”. Select all, delete.
• Search “Screenshot”. Delete hundreds in minutes.
• Search old years, like “2017”, review only those, delete duplicates and junk.

This targets big groups fast.
You reduce decisions per photo, which saves time and stress.
Do one focused 10 minute session per day, your storage drops fast.