Well, I ordered the book and tried the free version... The information is gold, there's no denying that; except the fact that the app has a tendency to crash when switching back to the app, after watching a video. It crashes about 70 percent of the time, and it seemed to happen more often, the further into the book I advanced. If they can fix the intermittent crashes, this app is very useful. I might purchase the full version of this app, though it really needs to work without having to be restarted every time. Mobile phone: Samsung Galaxy Note 4 with Android 6.0.1.
Nice summary of the knowledge assembled by the Compete Vocal Institute. Definitely worth downloading to see whether you're interested in learning more about singing this way. If it inspires you then you'll want to buy the book or the full app.
Quite impressive. I'm not a singer in fact I bumped in this by accident not knowing what to expect. I learned great deal about vocal cords and will have more respect for good singers and even for my own voice and using my voice better, abusing it less often and knowing what to do if it's gone for some reason. The app on iOS is more stable (nothing new when comparing iOS and Android I guess) but I wasn't able to watch he videos on Android for some reason the server seving the videos was down.
Train to Sing in Tune – Vocal Exercise, Warm-Up, Ear Training and Singing Lesson