Progressive Web Apps (PWAs) were a topic of discussion at the Google I/O developer conference held in May 2016. Although relatively new, many companies are already utilizing these powerful web applications. The Washington Post, with its large readership, and The Billings Gazette, with a much smaller circulation, are using PWAs to engage readers. The practical Currency Converter and Expense Manager PWAs are gaining fans, and so is Snapdrop, which allows users to transfer data across devices. PWAs are also being used for educational purposes. An example is Soundslice, which displays sheet music and includes an audio/video link so that the student can hear how the musical score should sound.

An in-depth look at the properties of these mobile web-app hybrid sites may explain why PWAs are becoming popular.
Developers define the properties of a Progressive Web App (PWA) as:
- Progressive. Because they are built with progressive enhancement as a core tenet, Progressive Web Apps work for every user, regardless of browser choice. And, if your progressive web app is online, it's already accessible for Android -- and all other mobile users.
- Responsive. They fit any form factor, so they will display on desktop computers, mobile phones, and tablets.
- Connectivity independent. PWAs are enhanced with service workers, allowing the app to be used even when the user is offline or on a low-quality network, such as 2 G.
- App-like. Because they are built on the app-shell model, PWAs have an app-like feel for the user. They offer app-style interactions and navigation features such as touchscreen navigation and page swiping.
- Fresh. Thanks to the service worker update process, PWAs are updated like web pages; simply using them gets you the latest version. There’s no need to wait for updates to install.
- Safe. Because they are served via HTTPS, PWAs prevent snooping and content tampering.
- Discoverable. PWAs are identifiable as “applications” thanks to W3C manifests and service worker registration scope, allowing search engines to find them.
- Easy Re-engagement. Features such as push notifications, make PWA re-engagement easy. Using Web Push API, these apps can send Push Notifications to end-users, even when the user’s browser is closed. This is possible because Service Workers can be restarted even when no tab is open, allowing push events to deliver notifications to the users.
- Installable. Users don't need to go to an App Store, search for the app, click Install, wait for the download, then open the app. Each of these steps loses 20% of the potential users. To install a PWA, users can just copy and keep the URL on their home screen, then open the link like an app. PWAs start instantly, without a commitment to get started.
Economics may also be powering the popularity of PWAs, for the simple reason that PWAs don't require as big of a financial investment when compared to the cost of creating a native app. Native apps must be designed to run on select platforms, but PWAs can run on every platform, browser, and device.
Let’s take a look at the technologies that power PWAs:
- Application Shell Architecture is used to quickly load an app-shell and to display the content dynamically.
- Service Workers for background script processes are used in offline mode. Although Service Worker helps with offline functionality, it isn’t supported by Apple’s Safari browser.
- Web Manifest or Extensible Web Manifesto technologies give PWAs a native-like mobile app experience.
- HTML5, CSS3, JavaScript, Media Queries, and jQuery-like Responsive Web Designing technologies are used to provide custom interactions with page elements.
- Transport Layer Security (TLS) protocols aim to provide high-end security and data integrity between two communicating computer applications.
These technologies allow developers to build PWAs - which in basic terms can be described as a fast-performance mobile website that behaves just like an app. Consider a PWA for your business when you need an application that can run on every browser and device without app store mediation. Since PWAs are less complex than a native app or website, they can easily be developed and come with the added bonus features of security and offline access.
Need a PWA for your business? Call AllianceTek today at 484-892-5713.
AllianceTek employs more than 100 talented and dedicated engineers with industry-leading technology skill sets. Headquartered in Malvern, PA, with offices in New York, California, Texas, and India, AllianceTek’s custom software development provides specific solutions for your industry that will align people, processes, and systems – and grow your business.