Doesnt work on my iPhone 6 plus

I used to highly recommend the app to several of my barbershop buddies and I used it on my previous iPhone 5. But it never worked on my new 6 Plus. It does not recognize nor can it play any of the loaded songs. In fact, the app stopped working. Send several emails to support. No answer. Totally frustrated and thinking abt switching to another similar app

Russkibass about Slow Down Music Trainer, v3.5.2