Scales Tutor for iPhone and Scales Tutor (for iPad) are available at the App Store. IMPORTANT fix to work with IOS 12 is in the works! Thanks for you patience!
                            For iPad, iPhone and Android (Bug fixes for IOS 12 compatibility are in the works. Thanks for you patience!)

  Scales Tutor for iPad     
  Scales Tutor (for iPhone)
https://play.google.com/store/apps/details?id=com.musikeys.scalestutor   Scales Tutor (
for Android)

Piano Technical Exercises: Interactive!