Hi Newbie here,
This will probably go down as the silliest question yet but here goes...
A piece of my property changed hands without my consent one dark and stormy night...
I decided not to stand for it again and set my mind to creating a GPS locator.
I bought a SIM808 from makerfabs.
I stuck in a Simcard with enough funds to sponsor small army.
I also fitted it with a 8GIG micro sd card.
I uploaded the sample sketch with my arduino 1.6.10
I started the serial monitor and lo and behold out jumped a whole slew of numbers and other related GPS coordinate detail.
At this time my tail was wagging furiously...
I then tried to figure out a way of getting my phone to talk to the GPS and hopefully get some GPS coordinates via sms back on my phone...nothing
My tail started drooping...
I consulted that much vouched for information source by name of google and YouTube but to no avail...
I am now slinking off into the dark with my tail between my legs peering back over my shoulder hoping for a reprieve from somebody on this forum....
I have no experience of the SIM808, but with the SIM908 you need to swap between modes. GPS mode, gsm mode. So read GPS co-ordinates (neoGPS seems highly recommended to parse the output) and the switch mode to GSM to send by SMS to... Back to GPS mode... If you want to be clever the SIM 808 (probably) has an internal clock so you can take a reading at fixed intervals.
There is a snippet about sending an SMS in my signature link.
Alternatively you could write to the SD card ? I don't know where that fits in your setup.
For this project I would recommend looking at the Adafruit Feather FONA which uses the SIM800 and includes an on-board MCU as well, which makes things really compact. You can use the GSM location function to get the latitude and longitude, speed, altitude, etc. of the device. I'd recommend looking at my slightly altered FONA library here.
Best of luck! 
Dear Friend,
I would like to know whether can I make a WIFI hotspot from Sim808 module and MCU8266. Or any recommended module to make a WIFI hotspot.