GILE_OSNAPPALETTE command shows the Onsap Palette which combines the OSNAP dialog toggles to set running Object Snap modes (possibly 'on the fly') and the Object Snap Menu to specify a command modifier (object snap, point filter, mtp) at a command prompt for a point.
The Onsap Palette also provides some custom Object Snap modes to snap on the Third, the Quarter or any other specified Fraction of curve lengths (arc, circle, ellipse, line, polyline segment) and on the Centroid of arcs, polylines, regions and 3D solids. These Custom Object Snaps also can be specified as a running mode via the _OSNAP command, by entering the object snap name at a prompt for a point, or with the osnap AutoLISP function.
A system variable (GILE_CUSTOSMODE) defines the running Custom Object Snap modes. Another one (GILE_COMODEFRACDEN) defines the fraction denominator for the FRC object snap. These system variables values can also be specified by entering their names, using the _SETVAR command, or, from AutoLISP, with the getvar and setvar functions.
Note: This app uses a custom installer (and not the standard App Store installer).