How to Make an Addon?

Hello,



How to make an addon?



I need to create an information page for my customers with dates of receipt of their orders.



In fact, I need to put a script in PHP or Smarty (I already have the scripts) on a new special dedicated only information CMS page or an other page.



```php Your order will be at your door {PHP}“Today + X Days”{/PHP} ```



How could I do?



Create an addon?



Thank you,





Lee Li Pop