Finding the right location of your body's joints in a video can be challenging and is important for accurate measurement. So for both Bike Fast Fit we encourage you to place dot stickers on the joint locations to make them easy to identify when setting up measurements. With Bike Fast Fit, anything you want to use to mark the joints is fine.
With Bike Fast Fit Elite the app uses the dot stickers to track the joints through every frame of the video and make a dynamic wire frame and dynamically track key measurements. So with Bike Fast Fit Elite dot stickers are required and should be about 3/4" to 1" in diameter and in a distinct color so the app can pick them out in the video. I have had good luck with a variety of office supply stickers.
Here are the ones I am currently using: ChromaLabel 1 inch Color-Code Dot Labels
I have also used these mini targets in the past: Birchwood Casey 360-1-Inch Target Spots
One inch stickers tend to work much better than 3/4" or even smaller stickers. Here is what 3/4" stickers look like in the video:
If you are in a pinch and don't have access to a sticker, I have had fairly good luck using blue masking tape. Just rip off a little strip and try to make it about 1". It won't be quite as reliable or accurate, but should work.
While round stickers with an inner dot might seem like a good idea and work in some locations:
In other places they can blend in with the surrounding area and make the app focus solely on the small inner dot: