custom wp plugin needed

I am in need of a custom Wordpress plugin that can allow via shortcode any page to display the distance in miles of a user from the Washington monument. You can use a third party API in order to make the distance calculations. Basically, any user that uses it must be able to get an answer for “what is my distance away from the Washington Monument?” It should return the distance in either miles or km or both. The display should look professional but can be basic. Also, try to include an endpoint of rest api that can return that distance to the Washington Monument