It requires a few steps, but i've just tested mine out and its working. Make sure that after you add a speed trap and go to the website, you toggle on "Speed Traps." I think by default the website is set to view crashes which might not be what you want to see.

1. Hold down on screen for 2 seconds.
2. Press the red "Submit" button
3. Enter in a Speed (you must be logged in to accomplish this)
4. Select the speed trap type
Njection does some crunching and adds the trap. You don't get any confirmation that the add was successful or that it failed, but you can check the site.