This Button is possibly the most important Button.
It can re-order Trackpoints on a L9ine between the two selected Points.
Let's see an Example.
We are in this Zoom-Level: 
Situation in the RAW GPX-File is this:
In the first step i will move Trackpoint 9 into the Center of the roads.
For this i will select TP 9 and then Move it using the H/V Buttons.
Now Situation looks like this:
Now I can use the "Line Points" Button, to move all Points between Trackpoint 1 and Trackpoint 9 on a Line.
For this i will select these two Trackpoints that mark the Start and End of the Line.
All Points between will be moved in a 90 Degree Angle towards this Line.
These Points are selected.
I press this Button:
Here we have the result. All Points between 1 and 9 are now on the Line.
Here we have another example.
