A simple spirit level that helps you to put things straight! Can also be used to measure angles.
The two displays shows the angle of the phone in two directions. If the angle is more than 45 degrees, it is not shown. This is because the values provided by the iPhone are not reliable at that level.
Freeze bubble button
The blue round button is the freeze bubble. If it is pressed, it it displays one freeze bubble each for the two glass pipes with the current angle. They stay up until the button is pressed again.
The calibrate button is the golden button with the sign -0- on it. Use it to set a new zero-angle if you do not want to use the default zero-angle provided by the iPhone. To return to the iPhone zero-angle, press the button again.
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