Thanks for the links. However, I failed installing iGO correctly.
I downloaded all the files and created the the iGO NextGen based folder. The folder structure is:
I added the folder license from another post.
I copied the iGO_NextGen folder to the android device (Sony Xperia Z2) and installed iGO NextGen_188.8.131.524935+sys.apk.
What did I do wrong or miss?
Thanks in advance