EasyATC...

EasyATC is a free third party air traffic control plugin for X-Plane.
EasyATC V4.Beta released
See the updates here

Download EasyATC 4.Beta
(and please check the executable file updates)
X-Plane.fr
X-Plane.org

A first video using EasyATC 2.0 in a VFR flight!

An IFR flight using EasyATC 1.1.

Cruise Altitude

When you Enable EasyATC, a dialog is displayed asking for the cruise altitude (among others items). The value you select replace any "9999" Altitude value of waypoints of the flight plan.
That means that when you create a chart of a flight plan and you put "9999" in the Altitude column that means that this value will the Cruise Altitude you pick-up when you enable EasyATC.