When working with Drupal as a backend for mobile applications, and serving the information via RESTful services, it is important to limit the number of needed requests from the site to the minimum.
Following my posts regarding to Paypal recurring payments, I was asked to fill the gap that was left there - how to setup the needed Rules in order to manage the payments.
When working with Drupal 6 mapping few years ago, there where limited number of mapping solutions, which mainly focused on the integration between gmap and location modules.
Drupal Commerce is the de-facto eCommerce solution for Drupal 7. Being so, it already has many different contributed modules that enhance its capabilities and make it much stronger, fit to answer any possible scenario.