I use Sky Safari 6 Pro on my iPhone 7 Plus. Suddenly today when I click on the Sky Safari icon on my desktop the Sky Safari splash page pops up, sits there for about 4 seconds, then the screen goes back to the desktop. I have erased all active apps, powered off, powered back on, tried again several times, same result. All my other apps seem to be working normally. I downloaded a copy of Sky Safari, which I had used prior to upgrading to 6 Pro, and it works perfectly.