Download the APK file to your computer
connect your phone to your pc, unlock your phone(swipe your screen or your pincode) so your phone memory appears.
Copy the apk file to your phone.( in the main directory or in a folder)
Start up a filemanager on your phone, install the apk (jp.co.polyphony.GTCourseMaker_1.0.0.apk)
When you get the message for third party app or something like that, enable that option.
let it install (takes a while the apk is 38mb)
after install open en enjoy.
Create a track, then hit export in the upper right, my app directed me to the login for psn, log in
the app exports to your psn account.
start up GT6, go to the right (the new coursemaker import icon) and get your file
testdrive 1 lap so it unlocks the save option, save the track and it's in your game.
done.
i used a samsung S5