First, Check version.
ODROID-C2
Install v1.0(Marshmallow)9 version or higher.
odroidc2-eng 6.0.1 MOB31K odroidc2-eng-s905_6.0.1_master-9 test-keys
Install v1.8(Lollipop)241 version or higher.
odroidc2-eng 5.1.1 LMY47V odroidc2-eng-s905_5.1.1_master-241 test-keys
ODROID-C1/C1+/C0
Install v3.0(KitKat)426 version or higher.
odroidc-eng 4.4.2 KOT49H odroidc-eng-s805_4.4.2_master-426 test-keys
Install v1.0(Lollipop)15 version or higher.
odroidc-eng 5.1.1 LMY48W odroidc-eng-s805_5.1.1_master-15 test-keys
Open Browser app and go to
http://opengapps.org.
ODROID-C2/C1/C1+/C0
Check
ARM, 5.1, micro and download.
You must select ARM not ARM64, because ODROID-C2 is 32bit OS.
You have to choose between nano and micro.
ODROID-C1/C1+/C0
Check
ARM, 4.4, micro and download.
You have to choose between nano and micro.
Open ODROID Utility app.
Select "Package install from storage".
Select "File Manager".
Open Download folder.
Select "open_gapps-arm-5.1-micro-20160623.zip"
Select "Process" and system will be reboot.
Recovery...
Select "Google Now Launcher".
To use the Google Play Store, GappsInstaller app is no longer necessary.
You can now use the latest version of the Google Play Store.