Sliding Pin
Tap (the Sliding Pin icon) to create a sliding pin support. The sliding pin support enables rotation at its tip point, and movement along the ground direction. It decreases the degrees of freedom (DOF) by 1.
To place a sliding pin, tap at any point on an existing element. Then optionally drag the pin axis to change the pin rotation angle. Rotation can be changed anytime by tap-and-drag on the support.
To replace an existing support with a sliding pin, start the Sliding Pin command from the context menu of the replaced support.