I noticed a new icon on the left of the screen that allows you to draw lines on the map.  Does this feature set navigation limits, or serve some other purpose, or is it simply a tool for drawing lines on the map?

When you tap the icon, you are able to draw lines on the map with your finger

The idea is to draw a circle, box or other boundaries on your map to use as visual guides while flying. The promise was that DJI would treat your drawing as a geofence that would limit the flight to areas within It, but that has not yet happened.

It's not a new feauture

Also there is an icon  in the lower right that looks like an eraser (just to the right of clear guides) that I have tried pressing and it does not seem to do anything. I thought it was an eraser to erase the guide lines but it does not do it. Does anyone know what that is?

i'm also intrested to know what the eraser button do....

Patinito Posted at 2015-8-7 21:49
Also there is an icon  in the lower right that looks like an eraser (just to the right of clear guid ...

The eraser erases the flight previous that is collected on the screen kinda like etch a sketch eraser! gets rid of to many flight paths since you recorded last.