How-To: Install Google Play Store on Android on ODROID SBCs
Open GApps (make sure to go to opengapps.org and NOT opengapps.com) is the easiest way to install Google Play Store and other Google services to your open-source Android distribution, like the ones available for ODROID devices.
If your goal is to simply install Android apps, take note that many apps do not require Play Store to be installed. Sites like apkpure.com allow many apps to be downloaded while keeping Google off your device. As always, take extra caution when downloading apps, especially from third-party sites.
Check out this tutorial by Codewalker on how to install Google Play Store. Although this tutorial was made for the ODROID-N2 / ODROID-N2+ / ODROID-C4 / ODROID-HC4, it should work very similarly on other versions of Android.
If you'd rather just watch the video, you can do that here: