Can't put saddle on dragons in dragon fire beyond

I can't place a saddle on dragons in dragon fire beyond and have to eat tons of food to get the hearts up. I'm very disappointed because I was looking forward to playing this game.  Also I notice that you can't hit the dragon either..... the mount icon does not work either no matter how much I tap it. The games is on my Apple iPad. It is not an old device either I just got it no more than a year ago.