Hi, I did not build this device but I am myself designing a frequency counter. This one is a very simple one, perhaps the simplest you can make with a PIC micro. What frequency are you trying to measure in your test ? I'd suggest to start with a low one. The site says it should work until 50 MHz but this is already out of specs for the PIC micro (if I remember correctly max. toggle rate for the T1CLKI would be about 16 MHz ... of course it can work on higher frequency if you are lucky but Microchip does not guarantee it will).
If it does not work at all, try to double-check all connection, the connection to the LED and LCD - check the contrast setting. do you see any activity on other pins except for the input ?