What was the point of obtaining GPS?

Question

In Teenage Mutant Ninja Turtles: Out of the Shadows, Casey Jones (Stephen Amell) went to the common bar and got his hands on a GPS to track the Rocksteady and Beebop, but he never used the GPS.

Turtles used blue liquid footprint to track those two.

What was the point of GPS if they didn't have to use it?

Answer 1

Casey Jones did use the GPS tracker.

After getting it from the bar tender

Casey tracks Bebop and Rocksteady

to the TCRI building (where Baxter Stockman transforms Bebop and Rocksteady)

Casey sees April O'Neil run out of the building and follows her into the alley, where he eventually meets the Turtles.

^{(The screenshot were made from my copy of the film)}