Cant download correctly...

I tried downloading this but it wont download. It keeps saying it cant and shows up as a white app with grey lines through it. So I thought maybe I have to get the other free version but when I try unlocking the full version on the trial version it just doesnt work. It is making me
Buy it... Please help... I love this game and really wanna play but cant =(

JJ15198 about Build-a-lot 4: Power Source (Full)