Google Contacts API gives client applications access to a user’s contacts list where the application can create new contacts, update or delete existing ones, or query for contacts that match particular criteria. This tutorial explains how to implement the API in C# and ASP.NET with OAuth 2.0.
Twilio has launched the Message Feedback API which monitors when end users receive messages. The API tracks actions that indicate when a message was received and reports the action back to Twilio. In turn, Twilio can tweak its services and delivery to adjust for network variances across the globe.