Attention! 1. String Ensemble is a SOUND PLUGIN for another app called Functional Ear Trainer. It's not a stand-alone application! Install FET first. 2. Moreover you need to have an in-app purchase "Sound Plugins" to enable them. To activate String Ensemble: 0. Install it. 1. Run Functional Ear Trainer. 2. Click on the "gear" icon in the Main Menu.