As you know Stable version of Magento2 is released and if you wanna  create a new module then you can follow below steps  to create a new module in Magento2 stable version.

Below are the list of files that you need to create in order to create a new module, my package name is Ktpl and module name is Brandmanager for this case.

1) Create module.xml at app/code/Ktpl/Brandmanager/etc/module.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
    <module name="Ktpl_Brandmanager" setup_version="2.0.0">
    </module>
</config>

2) Create composer.json at app/code/Ktpl/Brandmanager/composer.json

{
  "name": "ktpl/brandmanager",
  "description": "Brand manager adds the facility to manage store brands in Magento2",
  "require": {
    "php": "~5.5.0|~5.6.0|~7.0.0",
    "magento/module-store": "*",
    "magento/module-backend": "*",
    "magento/framework": "*"
  },
  "type": "magento2-module",
  "license": "GPL-3.0",
  "authors": [
    {
      "name": "KTPL",
      "email": "chirag.bhavsar@krishtechnolabs.com"
    }
  ],
  "autoload": {
    "files": [
      "registration.php"
    ],
    "psr-4": {
      "Ktpl\\Brandmanager\\": ""
    }
  }
}

3) Create registration.php file at app/code/Ktpl/Brandmanager/registration.php

<?php

\Magento\Framework\Component\ComponentRegistrar::register(
    \Magento\Framework\Component\ComponentRegistrar::MODULE,
    'Ktpl_Brandmanager',
    __DIR__
);

After placing these files run below command from Magento root.

sudo php -f bin/magento setup:upgrade
sudo rm -rf var/cache/*
sudo rm -rf var/page_cache/*
sudo rm -rf var/generation/*

This process will successfully register your module and you would be able to see you module at store -> Configuration -> Advanced -> Advanced section.