4DRoom is an extension of the 4Dice app that puts the viewer INSIDE a 3D cube, for analogy-based tutorials,
and then inside an actual 4D hypercubic room to explore 4D space. Instead of a square wall, as one sees from inside
a 3D die, the center of the view is a cube, one of the
8 cubic walls surrounding the center of a hypercubic
room.
4DRoom also introduces a Virtual Reality feature under the
"accelerometer" option that lets one rotate the device left and
right in space to substitute for the 4D rotation controlled by
2-finger left-right drag. This gives a good virtual impression
of actually being inside a 4D room.