Thought I'd add this here to clarify some doubts about the UI. Here's a screen shot of the app with all the controls labelled.
The main things to note are:
1. Blue box and green box. You can think of the blue box and green box like a sling shot. The blue box is where you want your subject to be and the green box is where it is right now. The app makes the drone close the error between blue and green to make tracking happen. Now try this. You can touch the blue box and drag it to a different point in the frame. This will actually control your drone to adjust it's framing to match your composition. i.e. green will be pulled by blue.
2. Buttons. I've labelled Cancel Tracking (self explanatory) and that button above it. That's the Re-center button and it works in two ways. When tracking is on, if you drag the blue box to a different location, and then press the recenter button it will cause the blue box to recenter on the screen. If tracking is not on but you're gimbal is off to an angle, hitting the recenter button will recenter the gimbal to home position (i.e in the heading of the drone).
And here's an excerpt from the main video showing the selection event on the UI.

The main things to note are:
1. Blue box and green box. You can think of the blue box and green box like a sling shot. The blue box is where you want your subject to be and the green box is where it is right now. The app makes the drone close the error between blue and green to make tracking happen. Now try this. You can touch the blue box and drag it to a different point in the frame. This will actually control your drone to adjust it's framing to match your composition. i.e. green will be pulled by blue.
2. Buttons. I've labelled Cancel Tracking (self explanatory) and that button above it. That's the Re-center button and it works in two ways. When tracking is on, if you drag the blue box to a different location, and then press the recenter button it will cause the blue box to recenter on the screen. If tracking is not on but you're gimbal is off to an angle, hitting the recenter button will recenter the gimbal to home position (i.e in the heading of the drone).
And here's an excerpt from the main video showing the selection event on the UI.