I want to create a robot arm that can grab a box - object tracking.

What is the easiest android app for object tracking and send coordinates by bluetooth?

I want to create a robot arm that can grab a box.

Plan:

The Android application of the mobile phone has recognized the color of the boxes.
The color coordinates are transmitted by bluetooth to the Arduino.
The Arduino controls the robot's hand (centered on the box) to take the box.

What is the easiest Android app for object tracking and send coordinates by bluetooth?
I am thinking to use Arduino (with robot hand) + + MobilePhone + Object tracking app + Bluetooth