After Heinz Doofenshmirtz from the 2nd Dimension tried to kill the boys and platypus, and after the Norm Bots were out of the area they were hiding it, Phineas decided to use it in order to go back home. However, he could only open a portal to the 3rd Dimension.
Later, after the team and the newly joining Candace manage to avoid doom, Phineas uses it to transport them to the next dimension, and then go across the entire clock as their chased by Norm Bots. It no longer appears after this point.
The device is an olive green remote with two buttons, a light blue screen and an antenna, which is used to open the portal to the next dimension.