Aside from the bulk of this thread having to do with the OTG cable itself and which end to plug into which device, you may need to do this (Android phone):
-Open SETTINGS on phone
-Open ABOUT PHONE/SOFTWARE INFO/BUILD NUMBER, rapidly tap 7 times to access DEVELOPER OPTIONS, enter PIN if prompted
-Return to SETTINGS menu, tap DEVELOPER OPTIONS
-Under DEBUGGING, enable USB DEBUGGING
under NETWORKING, tap USB CONFIGURATION, select MTP, exit SETTINGS
Turn off WiFi, enable AIRPLANE mode
1. Turn Spark on
2. Turn RC on - wait for green light showing linked to drone
3. Plug OTG cable into phone
4. Plug OTG cable into RC - should auto-load Go4