The following variants for an installation on an Android device are possible:
Installation from the Google Play Store
This is the easiest option, recommended by Android. The user only needs access to Google Play Store. Installation and update processes do not require the user to take any further action.
Installation via an MDM system
Depending on the MDM system used, this option provides an installation which is technically comparable to the App Store variant.
Side Loading - Direct app installation
Only in thoughtfully pre-defined scenarios, this should be considered as an option. The app is installed without processing through the Google Play Store. Installation instructions and the corresponding installation files can be found here: Installation instructions for the smapOne app via sideloading (Android)