The Sticky Note API is a simple service that produces an image of user-specified text drawn on a yellow background. While it is unlikely that a mobile app would ever use such a simple service, it provides a convenient example to explore how the parts of an API work together.
Clients and servers for a REST version of the Sticky Note API. For a complete description, please see Build a mobile app using Google Compute Engine and REST.
Clients and servers for a gRPC version of the Sticky Note API. For a complete description, please see Build a mobile app using Google Compute Engine and gRPC.