What is a Progressive Web App?

In the beginning, there was a smartphone, a device that could handle lots of business functions at once. But there came a time when it was crushed over by a bigger digital product, which was native apps. Exactly they have completely eradicated the need for huge and uncomfortable phone devices, as now all you need is located directly in the digital app stores for any given mobile operating system.

However, as time moved on, lots of business owners have gained a huge admiration towards the native mobile apps and want to create their own. Was it worth it though? Well, certainly not, since it takes a lot of time and money to develop, maintain and advertise one. With that in mind, there was another solution to their problem, which was a progressive web application. What is this type of web application development and why does it combine both the features of a web app and a mobile application? All of it will be revealed in the article below.

PWA or commonly referred to as progressive web app is a type of web app that is built on default and the common web stack, such as HTML, CSS, and JavaScript. However, what makes this kind of web app so uncommon is that it can potentially compete with any native app out there. As both the looks and feels that a user experience from both of them are very alike. Furthermore, with the help of certain and custom additions to the progressive web app, anyone can make a PWA from a regular website. Meaning that the development is really fast if compared to the native one, which is long and notorious. If you want to make it stand out even more, then you can easily, with the help of PWA development company, add all of the features that a native app has, like customer support, online push notifications, online purchases, etc.

Nowadays lots of websites can be primary examples of progressive web apps that are constantly taking over the target market. For example, Pinterest - if you are using this platform from a browser, you can make a shortcut to directly access the PWA from a home screen. If you open it up, the look of it will be almost identical to the native one, with no extra screens or windows. Furthermore, you don’t need a specific operating system to launch it, as it runs on any electronic device with an open Internet connection and a web browser. The only thing you need to do is log in and that’s it. Everything that has been said just now can be considered as a solid advantage for developing a progressive web application.

Apart from the similar and rich functionalities of PWAs, another interesting fact is that they are currently getting more popular. Starbucks, Twitter, Forbes, Uber, and lots of other big companies are the direct progressive web app examples that are competing with the native mobile apps.

On average it was estimated that during an initial introduction between a user and a native mobile app, close to 20% of all users are deleting it, without being utilized. What’s wrong? Well, the path or the journey of an app discovery may be a very long one. First, a user must find the desired app inside a digital store, then he must download it, install it, log in, and only then he can use it. So a user has to execute at least 5 definitive actions to use the app. And that might be a bit inconvenient to some people. A progressive web application, on the other hand, can launch its work almost immediately that completely eradicates the need for 2 or 3 stages.

But it doesn’t certainly mean that a native app is all that bad. On the contrary, push notifications can lead up to 3 times more retention with a user that will most likely reopen a mobile application more often compared to a website. With that being said, a progressive web platform takes advantage of this feature and more that can run on pretty much any device. Resulting in higher user satisfaction and engagement without the hassles of running or installing a mobile app.

Native apps, the ones that you can see on Apple Store or Google Play Store are always written in a specific or designated programming language. For iOS operating systems and applications that would be Swift, for Android it is Java. So, to develop such an app, you or your technology partner must be an expert with either both technologies or at least one of them (it depends on the platform you want it to be developed). There are various shortcuts that you may take, but all of them have significant drawbacks.

For that reason, lots of entrepreneurs and business owners have considered a progressive web application that can serve as a mobile app located in every phone’s browser. The PWA has access to various tools and hardware parts of your phone that a typical browser can get any access to, due to security concerns. More than that, almost every user won’t feel a difference between a real native application and a PWA, as it performs and behaves just like it.

But this technology doesn’t come with its drawbacks either. There is no doubt that almost all browsers were able to adapt the PWA technology. However, this small percentage that didn’t manage to adapt to it has certain limitations. For example, Apple’s browser Safari is not able to comprehend the progressive web app technology just yet. Apple’s team supposedly does not wish to fund this technology just yet.

As it was already mentioned, every progressive web application out there is built on the default web app stack (HTML, CSS, JS). It was a creation that combined both the native mobile features and the specificity of search engines to perform SEO tactics. Lots of PWAs are utilizing JavaScript to implement complex features, and while search engines have improved their ability to render JavaScript language, it may still be a source of concern.

So, one of the essentials you must do is to make all of your JavaScript files completely accessible to the search engine crawler. Test it out and make sure that every single “.js'' is available for anyone. In addition, you can also implement server-side rendering in your progressive web application to significantly increase the rendering process.

If you go ahead and redo your website to a progressive web application, it won’t guarantee or increase the chances that it will lift your SEO ranking. If you have a solid business plan that points directly to developing a PWA, go ahead. Provide your user with an enjoyable and delightful user journey experience that can outmatch your competitors, while researching the best tactics for your SEO strategy. But don’t develop it solely for the reason of enhancing your current SEO, it won’t do that much.

Just as any other type of web application out there, progressive web apps have their own, unique characteristics that can be certainly highlighted. It is especially important if you are in between the development choice and don’t understand whether you should pick PWA or not.

• Progressive - Just like the definition of a PWA says, it has to be progressive. Which is available on any kind of device and any given platform out there. More than that, the progressive web app should evolve with time and nurture more available features for the given user’s device.
• Discoverable - Since every progressive web app is both available and accessible over the Internet via browser, it should be highly discoverable for a specific search engine. It is a very good opportunity to get your web app noticed for the right target market. Unlike native mobile apps which are lacking proper awareness spread.
• Linkable - Just like a website, a PWA is designed to have a URI, which indicates the backend system of the current state of the web application. Exactly this factor allows the web app to retain or reload its state whenever the user is performing some dynamic action, like sharing the app’s URL, for example.
• Native App Feeling - A progressive web app should have both the feeling and the looks of an original native mobile app. Even though it was built on the regular web app stack, with a minimum amount of page refreshes.
• Offline Support - Depending on the type of progressive web app, it should either support partial or full offline experience whatever the circumstances are calling for it.
• Reusability - Almost every native mobile app out there engages users to constantly reuse their app features. The same rule follows progressive web apps, as they are trying to achieve the same goals here through push notifications and alerts on the user screen.
• Accessible - Any progressive web application has to be easily accessible and loadable from the user’s home screen.

The same thing goes for the benefits of implementing a progressive web app. While the characteristics may also look like direct evidence of an advantage, these points contribute to the comparison among other web app development processes.

Reliable

A PWA should launch and give users meaningful content regardless of network conditions. There is no doubt that the amount of functionalities that can be supported offline more highly depends on the type of web application. Some of them (like PWA fitness trackers, for example), may have complete offline support. The others, like an online Ecommerce progressive web app, should have a direct network connection with little to no offline features available. In both cases, the web app should not have any software breaks or any sudden unresponsive actions, thus, it should be reliable.

Responsive

Every single progressive web application has to match with various screen sizes and orientations, as it should be able to provide users with both a pleasant user experience and the flexibility of its usage. A strong responsive interface ensures that the software works for every modern and trending device that has been already released into the market.

Engaging

As it happens to be, native apps have been much more immersive than any web application deployed on the Internet. Push notifications directly assist the user with the crucial information that demands their immediate attention, while having an icon on the home screen makes it easy to access the app. Now that the progressive web apps have been widely used in our daily lives, lots of users will get the same experience that they usually receive from the regular native web app.

Secure

Most of the time, every progressive web app out there may have confidential and private user information. Therefore, the connection between a regular user and the data servers where all of this data is stored should be secured by default. Ergo, every single connection from every node out there is going through the HTTPS channel, to both avoid the man-in-the-middle attacks and any suspicious interceptions from the service workers.

The fact that all PWAs are running inside a web browser is their most striking and obvious aspect. Web browsers act as virtual machines or rather mediums for these types of web applications, that allow progressive web apps to run with their specific settings. While every single native mobile app has to be implemented on either (or both) the Android or iOS operating systems, a progressive web app needs a browser and access to the Internet for a user to start using it.

The majority of modern browsers that are very popular among users are supporting the existing progressive web apps (these are Mozilla Firefox, Google Chrome, and Edge). Others are still getting around the PWA technologies and are just starting to accept them (like Internet Explorer or Safari). After knowing all of that, let’s take a look at how exactly the PWA does work or what kind of architecture it has.

Service Worker

This part of the progressive web app architecture covers an abstraction layer or a JavaScript file that connects the frontend and the backend parts in a user’s browser. The Service Worker is in charge of all customer requests and has access to the cache and servers for data storage. It enables progressive web apps to run properly when the offline mode is enabled or when the user has a falty internet connection.

Web App Manifest

The Web App Manifest is a JSON file that defines a PWA's key parameters. For example, it can specify the name of an app in a browser, the app icon, the view of a PWA, and a variety of other features and small options. PWA itself can be installed as a standalone device on a smartphone screen using App Manifest.

HTTPs

As was already mentioned, the information and the data that is being stored inside the database of the PWA should be well secured. And for that HTTPS protocol has been integrated to ensure that the requested data can be passed through a secured medium. HTTPS encrypts the data with the SSL protocol, which means that an entrepreneur can confidently build banking apps or any other app where data encryption is crucial.

Appshell

Appshell or Application Shell is a layer applied to a progressive web app that simulates the feel and appearance of a native application. It is a skeleton of the Graphical User Interface (GUI) for progressive web apps and consists of the HTML, CSS, and JavaScript code embedded into it. It does also allow you to load the basic app elements and insert the data into them.

Push Notifications

Push notification is an alert message that appears on the user’s screen. The purpose of it can vary: from basic data notifications to new updates. Afterward, notifications may appear without even a user's interaction with a progressive web application, as it will notify the user about any occasional news, but only once he will register on the PWA platform.

Similar to other web applications, PWA has a wide variety of different programming frameworks and tools that allow its implementation. Here is a basic breakdown of each tool that is freely available for any developer who has a desire to create a progressive web app.

React.JS

Considered one of the most advanced and modern web app frameworks, React.js is a good fit for developing a progressive web application. React.js supports View mode from a default MVC model and allows embedding HTML into JavaScript files with the virtual DOM that renders web pages on a server-side. Even though this web framework is designed for large-scale projects, it is very flexible and is easy to learn.

Lighthouse

Google's Lighthouse is an automated tool used for auditing the accuracy of progressive web pages. It is a Chrome plugin that allows developers to test how a PWA works offline, loads websites, authenticates users, and tests other functionalities. This open-source performance audit platform identifies the program flows and assists in developing comprehensive and efficient PWA solutions.

Webpack

Webpack is a browser-based platform for compiling JavaScript modules. It is also widely used due to its results in efficient frontend development. Webpack assists in the creation of Service Worker and Web App Manifest. This platform enables the creation of dependable and high-quality PWA solutions.

With a rapid and quite fast speed of evolution of the progressive web applications, lots of different online resources about pwa development came to exist. And to keep up with the modern requirements of PWA development, Google has specifically created a platform for these purposes. To make it even more interesting, they have published a specific guideline where the Google Team has highlighted some important and essential actions that one should implement. Here are a few of them:

1. A progressive web app should run on any wireless device
2. The loading time of progressive web pages should be faster with a 3G connection
3. If loaded in offline mode, a PWA must be capable of handling most of the performance metrics high
4. All progressive web apps should be executable on any browser (that supports them)
5. HTTPS connection is a mandatory requirement
6. Every page must have a URL
7. Users are to be notified of the push notifications whenever any action or new data has been encountered within the PWA.

All in all, a progressive web app is a web app in its bare nutshell. And it doesn’t have any access to any digital mobile store. Should this be a big concern for you? Well, not at all. This can be a good opportunity for you to highly advertise and market your creation on the vast distance of the Internet. Compared to the audience on the digital stores (where one would need to invest a lot of work into pushing your app to the top of the chart), it can be easier for a business owner to popularize his PWA much faster. At the same time, the methods and the approaches for developing and delivering a progressive web app are an easier process, as you will already gain a basic audience with your first MVP deployment.