Connecting Yamaha Keyboards to Music Learning apps via USB Midi Host

[Kauaiguy]

Hi Guys!

It's been a while and although I can play the keyboard with accompanying styles I wanted to learn how to read music.  I found several internet music learning centers such as:  Simply Piano, Flowkey and Yousician.

I have chosen Simply Piano since it's starts at the very basic of learning to read notes, playing the correct keys with either Right or Left hand or both.

The problem is that their app/software requires that it listens to the notes being played to see if you're playing the correct note(s).  There are two ways to do this: a) via the built in microphone on your I-Pad, Android Device or PC :  But this is not always acurate since it sometimes doesn't hear the sound properly.
b)  And this is the best method Using a USB type B connected from your piano/keyboard (via Midi Host) and then to your I-Pad, Android device etc.

I have gone through a week of frustrations trying to connect my PSR SX700 to my Samsung Galaxy A7 Tablet with NO Luck.  After going through most of Joytunes Technical service people (which accomplished nothing), I finally called Yamaha Support and just found out that Yamaha doesn't support most of these apps.  That's why I couldn't make anything work.   However, it works on my Donner DEP20 piano ... but not on my Yamaha.

The question is:  Has any of you tried doing this with any success?  I find it disheartening because I wanted to purchase a Yamaha P125 to replace the Donner, but now it doesn't look like it will work with these learning applications.  Except for maybe Flowkey which I believe that some yamaha'a are bundled with.

Any help appreciated.  Thanks in advance.