This project describes the setup of a Raspberry Pi as a 3G router and Wifi access-point. You will find a number of instructions on the internet and this description is nothing new. It just ties all ends together and provides all necessary configuration files. It does not mean that you don't have to edit some files though.
The description is based on a fresh installation of Raspbian Wheezy. You should first try to replicate every step exactly (exactly!) as described here before you start your own experiments.
You should have some experience with Linux and the commandline and know how to find and read documentation (man pages, Google, forums). This is definitely no guide for absolute beginners.
Besides this README, all details are in the file Instruction.md. All directories below files contain (sample) configuration files and utilities. One of the steps during installation will be that you copy the contents of files to the root-directory of your Raspbian installation.
Some scripts in the bin directory are one-time helper-scripts useful during setup. They are not necessary for productive use of the router/ap.
Gavilaan: fixed getstatus.sh to work with raspbian/stretch