You do not need to pay anything accept the licensing for the Papago software.

To unsure it works make sure your phone is capable of receiving GPS coordinates before you enable Papago. There is a program called GPS viewer or similar in your phone, where you can see the location and signal strength of the satellite. Make sure the GPS device on your phone is activated and you have do that outdoors for at least 10 minutes for the first time to get a location fix.

The maps should be copied to the correct folder in your SD card. See the instruction found in the malfree website.