If you have to deal with rapidly moving objects or other material for which tracking does not produce satisfactory results the keyframing technique is what you want.
When you created a matte  you probably noticed that keyframe indicator was set ON automatically.

Every time you click Create Matte you make the current frame a keyframe.  To delete a keyframe simply click Erase All.

1. Start Traxim. Notice that initially Keyframe if set OFF.
2. Set both Track Enable and Keyframe Enable OFF:

3. Go to Frame 1.
4. Draw an outline of the flower. Note: Unlike tracking keyframing can be done for a single object only.
5. Create a matte. Notice that Keyframe is set ON.
6. Go to Frame 5 and repeat steps 4 and 5.
7. Play the clip back to Frame 1.

8. Set Keyframe Enable ON.

9. Play the clip. Watch frames 2, 3 and 4 as they are being tweened.
10. At the Frame 6 the process is interrupted:

This message means that no more keyframes have been created in that direction. In order to continue tweening, create additional keyframe(s)  ahead of Frame 6 ( for example at frames 9, 14, 19 and 24). First, do not forget to set Keyframe Enable OFF! Then, return to Frame 5,  set Keyframe Enable ON and click Play Forward.
11. Traxim can do keyframing both forward and backward. The result, however, depends on the direction. In other words, the result of keyframing from Frame 1 to Frame 5
     is slightly different from the one obtained with keyframing from Frame 5 to Frame 1.