The FX Effect panel is used to add and configure FreeFrameGL (FFGL) effects on Maps. 
Each Map in a Layer can have its own FreeFrameGL Effect assigned, multiple Maps can share the same FreeFrameGL Effect.

Please see http://freeframe.sourceforge.net/ for details and Effect download

To add an Effect:

Select the Map(s) in Map Panel or in Output Window

Double-click on the FX Panel or use the Menu [Mapping > Effects > Add FreeFrame Effect] 

Select the Effect Library File (dll on Windows, so on MAC/Linux)

Note: The number and type of effect parameters displayed, depend from the FFGL Effect Library.

To remove an Effect:

Select the Map(s) in Map Panel or in Output Window

Menu [Mapping > Effects > Remove FreeFrame Effect]

Effects Example 

3 Maps on 1 Output Window, from left to right: No Effect, Heat, Edge Detection