tkinspect is an inspector for Tk applications. It uses Tk's send command to retreive infomation from other Tk applications.
When you choose an application through the File/Select Interpreter menu, lists will be filled with the names of the procs, globals, and windows the the application. Clicking on one of those names will fill the value window with the definition of the proc, the value of the global variable, or various information about the window. The value window is editable and its contents can be sent back to the selected application.
Tcl commands can be sent to the seleted application using the Command: entry, or through a command line (via the File/New Command Line menu) interface to the application. The command line is nearly identical to Tk's demo rmt.
For further information, select a topic from the help window's Topics menu.