To use, you start by touching the screen, it will draw a line of 8 feet, and draw a post (a circle). Then you touch as close to the point in the direction you want the fence to go. It will draw another line in that direction. Click on the "end" button to end a line of fence. This is equivalent of digging an end post, and moving onto the next line. Click the "Gate" button to enter a gate. This puts the program into "gate mode". The next line you draw will appear as a gate. (angled off to the side). Gate mode will turn off automatically, so the next point you draw will be a section.
Click the "Length" button to pick a section length from 3 to 10 feet. The default is 8 feet. This length is persistant, meaning it does not act like gate mode. Say you select 10 feet. All subsequent sections added will be 10 feet, until you change it to another length. You can zoom in and out, but the touch coordinates will be messed up once you do so, in relation to the fence points.