No-code is taking the world by storm. A couple of months ago, Bubble.io announced their $100M Series A. Although I don’t really think no-code builders will make “technical co-founders obsolete” (TechCrunch’s words, not mine!), they do allow making ideas that would otherwise remain in an unopen drawer to become reality — very quickly.

Bubble apps on steroids?

You can build real apps, with real data, and real users with Bubble — without ever having to write a single line of code.

Web apps built with Bubble are pretty great because they’re accessible on any device with a browser (even from your fridge?). …


On a sunny January 2020 morning, it hit me that there was no app that allowed the world to track then-emerging COVID-19. I bought the domain coronavirus.app (can’t access it? check this), built the app as a PWA with a couple of friends, launched it, and then millions of people started using it.

Since then, we’ve received a surprising number of emails from our users highlighting a very particular problem:

“I’ve searched App Store/Google Play and I can’t find it. Where is the app?”

“Where is the app?”

A large portion of our user base — mostly regular people, not techies — just can’t…


Within the web of functionality we typically call Progressive Web App (PWA), there’s one that I’ve always found particularly interesting: push notifications.

I built Progressier to help developers make any site a PWA without having to write any code. So, in the process, I had to build a push solution. And oh boy…that wasn’t easy.

In this article, I’ll walk you through some of the challenges we encountered during the development process with Firebase/GCP and how we overcame them. Note that this article does not contain any code snippets.

Challenge 1: Personalization vs marketing

Push notifications…what are they for? Well, there are two main occasions…


A month ago, I published Your PWA is going to break in August 2021 to help developers deal with the then-upcoming changes in Chrome 93 that popped up in everyone’s browser console “Page does not work offline. Starting in Chrome 93, the installability criteria is changing, and this site will not be installable.

Google is backing off

Great news! A few days ago, Google decided to pause their plans. And it looks like those plans are going to be on hold for a while — if not indefinitely.


The backstory

In January 2020, I gathered a couple of friends and together we built — on a hunch — the very first COVID-19 app, modestly entitled coronavirus.app.


PWA installation on iOS (left) and Android (right)

One of Google’s best resources about PWA development is How to provide your own in-app install experience. Among other things, it explains in great detail how to create an install button and how to detect when a PWA has been installed.

It works great… on Chrome.

What does it take to make a browser-agnostic install button?

It wouldn’t be fair to expect Google to write documentation for other browsers. No problem. But since the whole point of PWAs is that they work everywhere, an install button should by definition be browser-agnostic.

(Side note: With Progressier, creating an install button is as simple as adding <button class="progressier-install-button"></button>in your code but if…


My (totally random) prediction: 52% of all PWAs will break with Chrome 93

UPDATE: On April 14, Google announced they would be pausing their plan to roll out this feature. Check out my follow-up article here.

If you have a PWA and you’ve recently looked at your console or app manifest, you may have noticed this message:

Page does not work offline. Starting in Chrome 93, the installability criteria is changing, and this site will not be installable. https://developer.chrome.com/blog/improved-pwa-offline-detection for more information

Or if you’re using Edge:

Site cannot be installed: Page does not work offline. The page will not be regarded as installable after Edge 93, stable release August 2021.

You see…


Right before 2020 turned into a global shitshow, I gathered a couple of friends and together we came up with an idea for a simple little app we thought would be helpful. Humbly called The Coronavirus App, our app ended up being used by more than 15 million people, making it — I believe — one of the most widely used PWAs ever.

I love the web. And I love PWAs. What’s not to love, really? With a PWA, you only have one code base to manage. Your app works everywhere. …


Spoiler alert: I found some intriguing patterns…

As one of the makers of The Coronavirus App (if the link doesn’t work, check this), I’ve received countless emails asking me whether the data that the app displays could be trusted. My answer has always been the same:

“We can’t really know. But that’s the best data we have at our disposal. “

With the Coronavirus App, the job was to synthesize data reported by official sources as quickly and accurately as possible — and making it visually accessible. We’re app developers — not epidemiologists nor government officials. So when government report…


The Coronavirus App has been helping the world track the spread of COVID-19 since January 28

Earlier this year, we built the very first COVID-19 PWA, humbly named “The Coronavirus App” (if you can’t access this link, check this). Progressive Web Apps (or PWA) are great. They offer the best of both worlds: they look and feel like native apps, but under the hood, they’re actually websites — built with standard HTML, CSS and Javascript.

In these turbulent times, the fact that The Coronavirus App was a PWA didn’t just help — it was probably one of the main reasons for its success.

Regain control of your own app

We were able to launch our PWA very quickly. We came up with…

Kevin Basset

Founder @ Progressier, ex-VP Marketing & Maker of the Very First COVID-19 PWA

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