How do you spot a mature platform? You look for its app store. Evernote, the platform for storing and accessing all kinds of things to remember, has created a gallery of products built with its API, which is expected to grow into a complete app store.
Microblogging status messages may be small, but they pack quite the mashup punch. Twitter (our Twitter API profile) itself makes up 8% of all mashups on Programmable Web. So, it's to be expected that two of the three status message mashups below use Twitter. The other connects to Facebook.