Is the LED pattern app for the N900 safe?

Ok I downloaded the LED pattern changer app from the Extras Devel and When I went to use it, it says warning this could brick your phone.... Now im not entirely sure what bricking your phone means but I know it sounds bad.. But this app sounds really cool and it would be nice to change the color of the LED so I could tell if I had a message or call I missed... So does anyone know if this thing is safe? Also if its not does anyone know if I could do it without bricking my phone?