A lot of our communication these days with each other is digital, and today one of the companies enabling that — with APIs to build chat experiences into apps — is announcing a round of funding on the back of some very strong growth. Stream, which lets developers build chat and activity streams into apps and other services by way of a few lines of code, has raised $38 million, funding that it will be using to continue building out its existing business as well as to work on new features. Stream started out with APIs for activity feeds, and then it expanded to chat, which today can be integrated into apps built on a variety of platforms.