V2.3: Bug fixedversion
V1.9, 2.0: Upgraded the build compiler
V1.7:
History lists remember the coordinates / modes
V1.5:
Minor changes in mode selection
V1.4:
Added the camera view as a background
V1.34:
-Set the max screen ratio for Galaxy S8
V1.33:
-Added Custom keyboard.
-Hide/show Menu bar
-Added Function list
V1.3:
-Added cylindrical z(r,t), cylindrical r(t,z), spherical r(t,p), and parametricx(u,v); y(u,v); z(u,v) surface 3D plots.