Add QR to https://instant.io/

qr-for-instant.io.user.js

// ==UserScript==
// @name         Add QR to instant.io
// @namespace    http://tampermonkey.net/
// @version      0.2
// @description  Adds a QR code ready for scanning next to the URL once a file is seeded.
// @source       https://gist.github.com/dscho/25479c59fb01e64db97097173d51b130
// @updateURL    https://gist.github.com/dscho/25479c59fb01e64db97097173d51b130/raw/qr-for-instant.io.user.js
// @downloadURL  https://gist.github.com/dscho/25479c59fb01e64db97097173d51b130/raw/qr-for-instant.io.user.js
// @author       dscho
// @match        https://instant.io/
// @grant        none
// @require      https://cdnjs.cloudflare.com/ajax/libs/qrious/4.0.2/qrious.min.js
// ==/UserScript==

(function() {
    'use strict';

    const makeQR = (e) => {
        if (e.hasQR)
            return;
        e.hasQR = true;
        const div = document.createElement('div');
        e.parentElement.insertBefore(div, e);
        var qr = new QRious({element: div, value: e.href});
        e.parentElement.insertBefore(qr.image, e);
    };

    const selector = 'a[href^="/#"]';
    const els = document.querySelectorAll(selector);
    Array.prototype.map.call(els, (e) => {
        makeQR(e);
    });

    const observe = (events, observer) => {
        events.map((event) => {
            if (event.type === 'childList') {
                Array.prototype.map.call(event.target.querySelectorAll(selector), (e) => {
                    makeQR(e);
                });
            }
        });
    };

    new MutationObserver(observe).observe(document, { attributes: true, childList: true, subtree: true });
})();