Courtesy of Derrin

APK Explorer & Editor [Github]

APK Explorer & Editor, an open source tool for examining the contents of an installed APK, is solely for checking the installed APK file.
APK Explorer & Editor (AEE) includes a set of open source tools primarily designed to explore the contents of an installed application on an Android device. In addition, AEE offers a feature rich APK/Split APK/App Bundle installer that allows users to select and install files from the device's storage.