I recently decided on using acitivities in my desktop, however I soon met the following problem.

When I use a qt application in my desktop, I realize it is not integrating well to the activities. As an example, I am not able to use the features of goldendict (which does not have a good alternative now) with kde activities.

Reproducible: Always

Steps to Reproduce:
1. Open a qt program, e.g. goldendict and set it to close and stay in the system tray. 
2. Open it in an activity. Close it back so that it stays in system tray.
3. Switch to another activity and try to reach goldendict again by clicking to its tray icon.
Actual Results:  
You will not able to see that goldendict opens in the current acitivity. If you switch back to the previous acitivity where you initially opened goldendict, you will see that the program actually opens there.

Expected Results:  
I would expect that when I open the goldendict from the system tray, I would see it in the current activity; not in the acitivity where I initially opened goldendict. This behaviour trims quiete a number of features of a program like goldendict and makes it inconvenient to use with activities.

There are similar problems with clementine music player, which I am not sure whether it is qt based or kde based.

In my opinion, system tray programs should not be related to activities. Any program which runs in the system tray should be reached from any activity.