Kitprog is a PSoC5LP based on board programmer/debugger hardware tool, it also works as a USB-I2C or USB-UART Bridge. With this hardware tool, you can program/debug PSoC 5LP without Miniprog3 or other hardware tool.
KitProg does not add anything to the C88CKIT-059, because KitProg is already part of the CY8CKIT-059 board!!
The smaller break-off section of the board (with the standard USB plug fabricated on the PCB is in fact the KitProg module which allows you to program a blank device and debug the target code. Once the target is programmed it is perfectly possible to break the board in two, leaving the target to run normally and to use the kitprog module to program other devices.