Released and supported by Instagram, this library allows Python applications to interface with the Instagram REST and search APIs. One can follow updates to this library on the Instagram Developer's Blog or the Stack Overflow community hub.
Gowalla, Foursquare, Yelp, Facebook Places, the list goes on. There's certainly no shortage of methods to tell people where you are and what you're doing while you're there. Startup Whatser, built on the SoGeo API for location-based apps, has jumped into the ring with a different approach to check-in services: to be useful.
Hall, communication and collaboration platform for teams and business, allows teams to integrate various apps through the Hall API. Hall offers a suite of tools and features that enable teams to communicate, provide feedback, and share work in a seamless fashion (e.g. chat, file sharing, video sharing, etc.). Hall believes the world is currently evolving to a new normal when it comes to communication and project completion.