Create Installer. Load Only for first time. i.e WordPress installer

Hi,

I'm working on my new project and need to have an Installer controller to install few things first.
If you wanna get some idea what I'm looking for, you can imagine the WordPress installer (for the very first time will install certain thing for you just with few clicks) .

My Question is:
What approach is the best practice to do like that?

1. My thought was to have a Welcome controller and check if it's the first time go to $this->installer else go to $this->homePage
   
2. Change $route['default_controller']
   
3. What else can be the best practice?  
   

Thanks for your help
Ardawan