This runs a web app where /lang/instance/user/hashtag returns an iframeable page with
all recent posts by a matodon @user@instance account that contain #hashtag
This is derived from the corresponding RSS feed (that’s why we only get recent posts). I counldn’t find a simple way to get this information via “proper” mastodon API, so I used RSS (like boomers do 😉).
For example: