Good while bad!

This app is fantastic, but every time i open it on my iphone 3gs it crash, freeze and this is very bad...

Why you dont update this app???
Last update is for 1 year ago!
You just sell it and dont pay any attention to customers?!
This is unbelievable for wolfram Co!

Mr.Geo22 about Wolfram Multivariable Calculus Course Assistant