Fix for the previous fix :)
Fix a potential crasher ( do not set up a callback for end of rotation effect on the very first cubit that belongs to a rotation if all belonging cubits have not been set up yet )
There's a real crash from the field in Firebase Crashlytics which must mean that Cubit.returnRotationAngle() returned null.Leave some message in case this happens again.
Add a 'withdraw move' button to the Solving UI state.
Progress implementing RubikCube.retObjectString()
Progress with the 3x3x3 Solver.
More support for the 3x3x3 Solver: more of the actual 3x3x3 solver mechanism.