Add a "Checkout complete page is viewed" event, so a Drupal Commerce 7.x site builders can trigger various actions exactly at this point of the checkout process.
Creation of this module is prompted by the fact that built-in Commerce Checkout sub-module "Completing the checkout process" or "When an order is paid in full" event does not always stay alive when a user returns back from a payment provider site. That`s because these events are triggered BEFORE redirection to a drupal site and this is the right behaviour in order to make sure the order is paid and we can proceed with the checkout. But the problem is that payment providers may differently handle redirection process and do it in a multi-step manner making events in the question dead for the moment user sees our "Checkout complete" page.