Small custom app specialist.
I'm the creator of Fliptabify (http://apps.shopify.com/fliptabify), the most popular Facebook store app on the Shopify App store and author of the popular PHP API client library (http://wiki.shopify.com/Shopify_App_Development#.E2.80.9CI.E2.80.99m_a_PHP_developer.E2.80.9D).
Simpthings doesn't have any reviews just yet. Have you worked with them before? Ask them to send you a review request via their Shopify Experts admin.