Gopher is a long-lasting technology that in its heyday was touted as a plausible alternative to the World Wide Web. Content is accessed using a simple, text-based protocol detailed in IETF RFC 1436.
Nowadays, a small group of servers are maintained by hobbyists and educational organisations. There's still a lot to see and experience! You just need to dig a bit :)
Thus, DiggieDog is a Gopher client for Android.