Mouse Test 2 by Marco Baye - Released in June 16, 2016.  This is really a neat diagnostic utility that can aid you in figuring out what type of mouse you have connected to your Commodore 64.  When you plug in a mouse it recognizes, the program will move the appropriate sprite on the screen letting you know what you have.  Included in the archive is the full assembler (ACME) source code.