Progressive Web Application Qualities/Principles:

Source: Progressive Web Apps and the Windows Ecosystem [Build 2017] — Aaron Gustafson

Progressive

Browser Support — Works for every user regardless of browser choice. Support all popular browsers such as Microsoft EDGE, Chrome, Firefox, and Safari.

Platform/Device Support:

Responsive

All pages should be 100% Responsive. If your web Application is not responsive then all modern browsers might flag your application. Check your website with Google’s Mobile-Friendly Test.

Here are some of the Frameworks and guidelines help building the Responsive application:

As you see above in Google Trends Bootstrap is the number One front-end framework to build responsive applications.

Network Independent/Offline-First

Use Service Workers to make your application available even when there is no Internet connection or low-quality networks. Google’s Service Worker samples.

Eliminates network challenges

Resilient to any network conditions

Service Worker Design

App-Like — Optimized for Touch support

A PWA should feel like native applications with Touch, Gesture and Scrolling interactions. Full-screen, Splash Screens, Linkable and app like navigations are to PWA as well.

Fresh

Always up-to-date using service worker update process. Automatic sync in the background.

Secure

Website Loads over HTTPS. HTTPS helps to create an Encrypted channel between User and Web Server. Serving application behind TLS helps to prevent snooping and data tampering. It is a requirement for Service Workers.

Discoverable

W3c Manifest and service worker registration helps to allow search engines to find the application.

Sample Web App Manifest

Re-engageable

Push Notification type of features keeps a user engaged with your application. Service Workers and HTML5 notification together help to build such capability into your application.

Installable

Ability to add to Application to Home Screen. Ability to access the application without opening browser every time. This is possible by creating a web app manifest. Which allows you to set an Icon and Name of the application for your Home Screen.

Guidelines

Sample

Accessibility

In a software business what we do is create value for users and customers and If we do not consider accessibility today then we are doing our job well. Bringing accessibility into your web applications or website does not require a lot more effort other than few extra HTML attributes and appropriate messages and navigation to make your application available for disabled individuals.

Specification