The Gemini protocol is brutally simple, which makes it just about too useless for apps, tracking, and commercial purposes. Gemtext, the format for Gemini pages, is very basic; with about half as many features as markdown, it's barely a step above plain text. As a result, Gemini is a small universe of blogs and personal sites.
Its simplicity makes it easy for people to create compatible clients and services for it. It's self-hosting friendly and there are also hosting services, like smol.pub and some pubnixes.
Of course, you'll need to get a Gemini browser or visit a Gemini-to-web proxy to access it.