I've been using XnView for this on Windows, it has a side-by-side comparison mode where zooming into one image zooms into the other at the same time, so you can take several pictures of the same scene, then compare details side-by-side and delete the inferior ones until only the best is left.
I sync all my phone's photos with my computer, compare them on the computer, and the deletions sync back to the phone. It would be nice if there were an Android app that does this directly on the phone, though. Know of any?
(Similar to Side-by-side image viewer for Android with RAW (DNG) file support except that one didn't get answered, because it was based on a misunderstanding of raw images.)