Is there any module for Restful API in drupal 7 with commerce
Both Drupal and Drupal Commerce support API integrations with mobile apps.

Look into the following:


Start with Services for basic web service support in Drupal.
Throw Commerce Services on top of it to expose Drupal Commerce entities.


There are a couple of good articles by Tyler Frankenstein:


Drupal Services Example
Build a Mobile App to Sell Products with Drupal
Sell products with a custom mobile app a Presentation with Scott Hooker (then Commerce Guy) at DrupalCon Austin