Secant Method - App

My first app ever developed for Android.
This app will help you to determine the root of a simple function, this is very useful for Numerical Analysis.
The recognition of simple functions (i.e. F(x)=x³+2x²+10x-20=0) is working pretty well so the next step will be add support for more complex syntax.

For now is only on the Play Store, but I'll also publish it on Amazon soon.

Feedback will be appreciated.

Link: https://play.google.com/store/apps/details?id=com.plr.secmet