If you're looking for a simple and powerful math graphing calculator with f(x)=0 solver this is the right app for you!
You can also do discrete data graphs and view their statistics, by the way press on "Stats" before "All Graphs" to select the sets you want to plot.
Statistics and graphs 1 variable
Statistics and graphs 2 variables
Zooms on graphs etc.
This app version contains ads if you want the PRO version search for "Interactive Graphs PRO"