Party castbars for yourself and your group/raid member.
Yellow bar turns green on successful and red on unsuccessful/interrupted casts.
Colors can be tuned to your liking in the Custom Options Tab.
If the color change is unwanted go into the Animations tab, scroll down to Finish and delete "Duration" and uncheck the Custom Function for the color.
Player castbar is enabled by default but can be turned off in the Trigger Tab -> check "Ignore Self"
The "Threshold" slider can be used to compensate server lag. It marks a cast as successfull "x" seconds (standard is 140 ms) before the actual cast is completed. If you have a better or worse internet connection you may want to adjust this setting.
Castbar Icon and Cast time duration can be turned on in the Display Tab.
Cheers