Microsoft OneNote is a notebook tool to take and organize notes. The OneNote service API allows developers to integrate and manipulate OneNote user data in their own applications on a variety of platforms and devices. This code sample gives users examples of how to use OneNote API with Windows Phone.
Popular cloud-stored notes app Evernote recently announced its first contest. Developers can use the Evernote API to build apps that help users remember and track anything using photos and text. The contest is serious, with big prizes: $50,000 to the winner, and $50,000 more in prizes up for grabs.
A mobile app using the Google Analytics API ran into a really good problem to have. It got popular. The Analytiks app had enough users that it was frequently going beyond the 50K requests per day allotted to each developer. Each users has to authenticate, but then all share a single pool of requests. By contrast, the Twitter API's per-user limit makes more sense.