Progressive Web App

Progressive Web App (PWA) is a web site that a client can progressively enhance into a standalone app that's comparable with a native app.

Built on the basis of good adherence to modern web standards and technologies; they are platform independent, can be accessed through a URL, accessible and indexed by search engines.

A typical PWA will usually have included a high proportion of the following features and capabilities:

Load over HTTPS
Load over offline/poor performing network conditions (typically with a service worker script)
Prompt user to Add to Homescreen
Have a design that's mobile friendly
The web site is progressively enhanced
Optimised assets and requests, sometimes including delivery over HTTP2
Provide enhanced accessibility features such as using ARIA attributes

IndieWeb Examples

Calum Ryan with calumryan.com

Calum Ryan on calumryan.com

Jeremy Keith with adactio.com

Jeremy Keith on adactio.com

Articles

What, Exactly, Makes Something A Progressive Web App? https://infrequently.org/2016/09/what-exactly-makes-something-a-progressive-web-app/
Designing Responsive Progressive Web Apps https://cloudfour.com/thinks/designing-responsive-progressive-web-apps/

Tools

Lighthouse audit tool (Chrome extension) https://chrome.google.com/webstore/detail/lighthouse/blipmdconlkpinefehnmjammfjpmpbjk
PWABuilder http://preview.pwabuilder.com/

Quickstart

The below code is a quickstart for creating a PWA manifest for a social reader called Monocle:

{
    "name": "Monocle",
    "short_name": "Monocle",
    "description": "An IndieWeb Reader",
    "icons": [
        {
            "src": "/icons/android-chrome-192x192.png",
            "sizes": "192x192",
            "type": "image/png"
        },
        {
            "src": "/icons/android-chrome-512x512.png",
            "sizes": "512x512",
            "type": "image/png"
        }
    ],
    "id": "/?source=pwa",
    "start_url": "/?source=pwa",
    "background_color": "#fff",
    "display": "standalone",
    "scope": "/",
    "theme_color": "#fff"
}

Notes:

start_url is the URL that will first open when someone creates the PWA.
"display": "standalone" tells a device to display the PWA as a standalone application instead of being wrapped in the browser.