Here is my app, that you can buy on the Apple Store and use with your keyboard, if you want to see the chord you play, displayed on your phone, while you play.
You connect your instrument and your phone using a "usb to lightning" cable, or via bluetooth, if you have a midi bluetooth adapter.
Here is the link to the app website for more details : DisplayChord.arfntz.fr

See you soon,
Frantz.