Crashes on graphs

I love this app but when i use the graphing feature, it ALWAYS crashes and the app closes. Also what is annoying is i cannot use it in landscape mode. If the creators fix those issues i will give 5 stars. It also must be fully stable on the iPod Touch 4, which is what i have.

Wolfie Darkpaw about RK-83: Scientific Graphing Calculator, v1.2.3