I received an email from Blackview to solve uncalibrated tools:
Enter *#87# on dailing interface (Phone number pad), click gravity sensor to calibrate it.

Hello guys, For those with untuned tools in the Tool Bag, such as  1) Pic-Hanging 2) Gradienter  3)Plumb Bob Here is the solution. Solution is provided from an email sent to me from Blackview. I like to share with You here: Please enter *#87# on dailing interface, click gravity sensor (G-sensor) to ...

The tools in the ToolBag App in BV9900 are not calibrated properly. Will there be a software update?
If the tools are not set properly from the start, they are useless.