App Installer will scan your internal storage or SD card(s) for apk files and show you a single unified list of all the apps you can install.
Then, it will only take one touch of the finger to either install the app, or delete the apk file.

IMPORTANT NOTICE: if your device is running Android 11 or newer, in order for the app to be able to scan your device for the APK files you have copied/downloaded from other sources, you will have to allow for the "All Files Access Permission" when prompted, otherwise the scan will fail and the app will be useless.