What are Progressive Web Apps and should you build one? This presentation looks at the problems PWA is aiming to solve and shows you how to get started.

1. D E M Y S T I F Y I N G
P R O G R E S S I V E W E B A P P S
@ M A R C U S H E L L B E R G
5
S T O R Y A N D P H I L O S O P H Y
Software is eating the world and what most of us see of it is the user interface. The user
interface has become the key component of how the users experience the business
behind it. Competition is lost or won due to user experience. Simplicity is king and the
users get frustrated by anything ugly, slow or not working on the device they happen to
use at the time. We at Vaadin fight for simplicity and invite everyone to join this fight.
Together we want to build a user interface that puts a smile on the user’s face.
Vaadin is the technology that empowers developers to build the best web-apps for
business purposes. Our priority over everything else is developer productivity because
we believe that by simplifying the developer experience and saving the developer’s
time, they are best able to focus on building great user interfaces.
Our brand is what we want everyone to think about us. When everyone - both us and
the people around us - have a consistent understanding of what Vaadin is and what we
stand for, it enables that image to spread and amplify. This book defines what we want
that image to be. It defines what the Vaadin brand is.
I hope that You are as excited and proud of living and breathing the Vaadin brand as
I am. You are the one who is shaping what everyone thinks about Vaadin - using this
brand as a tool and a guideline every day.
Let’s fight for simplicity for both the users and the developers!
Joonas Lehtinen
Founder & CEO
Vaadin
I N T R O D U C T I O N

3. A P P I N S TA L L S / M O N T H :
0

4. While we haven’t yet reached ‘Peak App’ the market
is definitely tightening, and app publishers need to
rethink how to break through to the consumer’s
screen.
comScore 2016 US Mobile App report
comscore.com/Insights/Presentations-and-Whitepapers/2016/The-2016-US-Mobile-App-Report

5. Despite significant investment and hopes for positive ROI,
mobile applications are not paying off for many
brands.
Compelling alternatives such as progressive web apps
mean the branded app economy is poised for change.
gartner.com/smarterwithgartner/gartner-predicts-2017-marketers-expect-the-unexpected
GARTNER: 20% WILL ABANDON THEIR
MOBILE APPS BY 2019

6. T H E P R O B L E M I S F R I C T I O N

7. open the app store80
find your app in the store64
tap install51
accept permission requests41
find the app on their home screen33
26 will open the app
O U T O F 1 0 0 I N T E R E S T E D P E O P L E

9. tap install80
accept permission requests64
find the app on their home screen51
41will open the app
S T I L L , O N L Y . . .

10. C O S T P E R I N S TA L L
$ 1 . 5 0 +
fiksu.com/resources/fiksu-indexes

11. Users spend almost
90% of time in their top
5 apps.
Source: comScore 2016 report

12. W H AT A B O U T M O B I L E W E B ?

14. 80 will open the app
O U T O F 1 0 0 I N T E R E S T E D P E O P L E

15. Source: comScore 2016 report
0
3
6
9
12
# Visitors (MM)
0
50
100
150
200
Minutes
3x 20x
Native apps Mobile web
Top 1000 Mobile Apps vs. Top 1000 Mobile Web Properties

16. H O W A B O U T H Y B R I D , T H E N ?

17. WHAT'S HOLDING BACK THE
MOBILE WEB?

18. 1 . B A D U S E R E X P E R I E N C E

21. 2 . P O O R R E - E N G A G E M E N T

24. 3 . P E R F O R M A N C E

25. P R O G R E S S I V E W E B A P P S

26. 1. Reliable
2. Fast
3. Engaging

27. T R Y B E F O R E Y O U B U Y

29. H O W D O Y O U B U I L D A P W A ?

30. P W A C H E C K L I S T :
Site is served over HTTPS
Responsive layouts, works on mobile
First load is fast even on 3G
Site works cross-browser
Page transitions don't feel like they block on network
Each page has a URL
Metadata is provided for Add to Home screen
developers.google.com/web/progressive-web-apps/checklist

31. D O Y O U N E E D T O S TA R T F R O M
S C R AT C H ?
N O .

32. 1 . A D D A N A P P M A N I F E S T

33. {
"name": "Todo App",
"icons": [{
"src": "todo.png",
"sizes": "192x192",
"type": "image/png"
}],
"start_url": "/index.html",
"display": "standalone",
"orientation": "portrait"
}
https://developer.mozilla.org/en-US/docs/Web/Manifest
W E B A P P M A N I F E S T

34. <head>
...
<link rel="manifest" href="/manifest.webmanifest">
</head>

35. 2 . D E F I N E A S E R V I C E W O R K E R

36. Service worker

S E R V I C E W O R K E R

37. if ('serviceWorker' in navigator) {
}

38. if ('serviceWorker' in navigator) {
window.addEventListener('load', () => {
navigator.serviceWorker.register('/sw.js');
});
}

39. let CACHE_NAME = 'cache-v1';
let urlsToCache = ['/', '/styles/main.css',
'/script/main.js'];
/sw.js

40. let CACHE_NAME = 'cache-v1';
let urlsToCache = ['/', '/styles/main.css',
'/script/main.js'];
self.addEventListener('install', event => {
});

41. let CACHE_NAME = 'cache-v1';
let urlsToCache = ['/', '/styles/main.css',
'/script/main.js'];
self.addEventListener('install', event => {
event.waitUntil(
caches.open(CACHE_NAME));
});

42. let CACHE_NAME = 'cache-v1';
let urlsToCache = ['/', '/styles/main.css',
'/script/main.js'];
self.addEventListener('install', event => {
event.waitUntil(
caches.open(CACHE_NAME)
.then(cache => cache.addAll(urlsToCache));
);
});

43. self.addEventListener('fetch', event => {
});

44. self.addEventListener('fetch', event => {
event.respondWith(
);
});

45. self.addEventListener('fetch', event => {
event.respondWith(
caches.match(event.request)
);
});

46. self.addEventListener('fetch', event => {
event.respondWith(
caches.match(event.request)
.then(response => {
if (response) {
return response;
}
return fetch(event.request);
}
)
);
});

47. github.com/GoogleChrome/sw-precache
github.com/GoogleChrome/sw-toolbox
toolbox.router.get('*.json', toolbox.cacheFirst);->
T O O L S

48. 3 . A D D P U S H , B A C K G R O U N D S Y N C
( I F Y O U W A N T T O )

49. developers.google.com
😅
/web
/fundamentals
/getting-started
/codelabs
/push-notifications

50. Lighthouse

51. T H E B A D N E W S

52. N O I O S S U P P O R T
(YET)

53. T H E G O O D N E W S

54. G R E AT A N D R O I D S U P P O R T
(88% MARKET SHARE)

55. A N D D E S K T O P O F C O U R S E

56. T H E Y A R E A P R O G R E S S I V E
E N H A N C E M E N T

57. C A N B E U S E D W I T H A N Y
F R A M E W O R K
P A R T O F T H E W E B P L AT F O R M

60. Help developers build
web apps that users ♡

61. T H A N K Y O U !
@ M A R C U S H E L L B E R G
5
S T O R Y A N D P H I L O S O P H Y
Software is eating the world and what most of us see of it is the user interface. The user
interface has become the key component of how the users experience the business
behind it. Competition is lost or won due to user experience. Simplicity is king and the
users get frustrated by anything ugly, slow or not working on the device they happen to
use at the time. We at Vaadin fight for simplicity and invite everyone to join this fight.
Together we want to build a user interface that puts a smile on the user’s face.
Vaadin is the technology that empowers developers to build the best web-apps for
business purposes. Our priority over everything else is developer productivity because
we believe that by simplifying the developer experience and saving the developer’s
time, they are best able to focus on building great user interfaces.
Our brand is what we want everyone to think about us. When everyone - both us and
the people around us - have a consistent understanding of what Vaadin is and what we
stand for, it enables that image to spread and amplify. This book defines what we want
that image to be. It defines what the Vaadin brand is.
I hope that You are as excited and proud of living and breathing the Vaadin brand as
I am. You are the one who is shaping what everyone thinks about Vaadin - using this
brand as a tool and a guideline every day.
Let’s fight for simplicity for both the users and the developers!
Joonas Lehtinen
Founder & CEO
Vaadin
I N T R O D U C T I O N