Q. Are there other streaming APIs that I can use to create applications like this?
A. Yes. An increasing number of streaming APIs is becoming available to developers. At the time of writing, some APIs of interest include Campfire, Salesforce, Datasift, and Apigee, with many more expected to be created.
Q. How accurate is this data?
A. Not very. This data is based on the “statuses/filter” method from Twitter’s streaming API. More information about what goes into this feed is available here https://dev.twitter.com/docs/streaming-api/methods. In short, do not base any anthropological studies on it.
Q. Can I save this data somewhere?
A. The application created in this hour does not persist data anywhere, so if the server is stopped, the counters and percentages are reset. Clearly, the longer that data can be collected, the more accurate the results. The application could be extended to store the counters with a data store that can handle high volumes of writes like Redis. This is outside the scope of this hour, though!