About

About is an Android utility app for developers & testers who juggle APK
variations. It quickly shows the version name, version code, and certificate
hash / signature for installed APKs and for the base system image.

About runs on Phone/Tablet (including as a widget), Wear and TV.

Q. Why not use Android->Settings?
A. Android Settings isn't great for disambiguation of different certificate
versions etc, and isn't as quick.