json files were widely used for hold data for apps and web services. Reading and writing speed of json will be faster than expected, in effect app using json will fetch data from web in a quick way.

So where should I put the json on the web ?, Google drive formerly support the accessing of json file directly, soon they removed this feature. Or you can host those files on your own server

With GitHub pages can host json file which can accessed by any app. The url would form like

<username>.githubio/<json-file>

You can create one GitHub page per user and unlimited on Organization. In either case you repository name should match the <organisation name> / <username>.github.io. You can add folders and files inside the repository

for more guide how to create GitHub Pages go to the official GitHubPage Site