Android (Chrome, Edge, Samsung Internet)
- Open the app’s website.
- Tap the “Install” button on the page or, in the browser menu (⋮), “Install app”.
- The icon appears on your home screen like any other app.
Technology in plain words
What is a PWA — an app you install straight from a website
A PWA (Progressive Web App) is a website that can behave like an app: it goes onto your phone’s home screen without a store, opens without internet and updates itself. We build real working systems on this technology — and four games so you can test it yourself.
Works on Android, iPhone and computers
In short
A PWA is an ordinary website taught four things
No magic: modern browsers can do all of this themselves when a site is built the right way.
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Installs from the website
Open the address, tap “Install” — the icon is on your screen. No App Store or Google Play, no sign-up, no hundreds of megabytes to download.
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Works without internet
On the first visit the app saves its files on the device. After that it opens even in flight mode.
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Updates itself
A new version downloads in the background while you use the app. No “please update in the store”.
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One app for everyone
Android, iPhone, Windows, Mac — one address and one codebase. Cheaper to build and to maintain.
Installing
How to install a PWA
Two or three taps on every platform. Nothing to download in advance.
iPhone and iPad (Safari)
- Open the website in Safari.
- Tap “Share” — the square with an arrow at the bottom of the screen.
- Choose “Add to Home Screen” and tap “Add”.
An iPhone never suggests installing on its own — only through the Share menu. The app then opens full screen, without an address bar.
Computer (Chrome, Edge)
- Open the website.
- Click the install icon at the right of the address bar (a monitor with an arrow).
- The app appears in the Start menu or the Dock and opens in its own window.
Offline
Why it works without internet
Inside a PWA there is a small “helper” (called a service worker). On the first visit it stores the needed files in the device’s memory, and afterwards answers the app’s requests itself — from that memory, without going online.
That is why the app opens in a lift, a basement or a plane. When the connection is back, it sends the data it collected to the server and pulls down anything new. Our TelliApp Workshop works the same way: an intake with photos and a signature is completed even without signal and sent to the server later. Invoices, payments and sending documents need a connection.
The high-score table in TelliApp Games works the same way: a record set in airplane mode is kept on the phone and goes to the shared table by itself as soon as the internet is back. The game shows “The record will be sent when you are back online”, then “Sent”.
- Opens in flight mode
- Data is not lost
- Syncs when the connection returns
Updates
How a PWA updates
Every time the app is opened with a live connection it quietly checks for a new version. If there is one, it downloads it in the background and offers to switch when it suits you. Users never have “old versions” to update by hand in a store, and a bug fix reaches everyone in minutes rather than after days of store review.
Comparison
How a PWA differs from a store app
Honestly: each option has its strengths. We will tell you which one suits your task.
PWA
- Installs from a link, no store and no 15–30 % commission
- One version for every device — cheaper to build and maintain
- Updates instantly, no store review
- Does not take hundreds of megabytes
- Can also be opened simply as a website — no install needed
App from the App Store / Google Play
- More visible: people find it in the store
- Full hardware access: Bluetooth, NFC, background work, widgets
- Notifications on iPhone are set up the familiar way
- Needs store publishing and developer accounts
- Two codebases (iOS and Android) or a cross-platform framework such as Flutter
How much space it takes
- TelliApp Games — four games, graphics and sound
- ≈ 2.1 MB
- A typical game from a store
- usually from a hundred megabytes to several gigabytes
The size of TelliApp Games is counted when the site is built — all the app's files together. How much they take on your phone is shown in the games menu, where one button also removes them.
Limitations
What to know in advance
Checked against Apple’s and Google’s documentation at the time of publishing.
An iPhone does not offer to install
On Android the browser shows an “Install” button. On iPhone there is none — only “Share → Add to Home Screen”. We show an illustrated hint right on the page.
Notifications on iPhone only after installing
Push notifications on iPhone and iPad work since iOS 16.4, but only for apps added to the Home Screen and only with your permission.
On iPhone every browser is Safari’s engine
Chrome and Firefox on iPhone are built on the same WebKit engine, so PWA capabilities there match Safari’s. In the European Union Apple allowed other engines, but Home Screen web apps still run through WebKit.
No Bluetooth, NFC or background work
A PWA cannot talk to Bluetooth devices or NFC and does nothing in the background while closed (on iPhone even less so). For a barcode scanner, the camera and location the capabilities are enough.
Storage can be cleared
When a device runs out of space, the system may delete websites’ saved data. A site not used in Safari for seven days may also lose its data — apps installed to the Home Screen are exempt. That is why important data lives on the server.
The installed copy is separate
On iPhone the Home Screen app and the same site in a Safari tab keep their data separately. A game record set in the tab, for example, will not show up in the installed copy.
Try it yourself
Install TelliApp Games, switch on flight mode and find the secret
Four small games built on this technology: “Defend the Server”, “Up the Signal”, “Data Centre Flight” and “Last Signal”. Install the app from the website, open it at least once — then switch off the internet. The games keep working, and each unlocks a secret mode. No sign-up, no ads, no collection of personal data: only the nickname you choose yourself goes to the shared high-score table.
Address: telliapp.ee/play — open it on your phone
In production
Real systems of ours run on this technology
The games are for show. In real life a PWA keeps business processes running every day.
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TelliApp Workshop
Order tracking for a repair service: intake with a signature, status by QR code, price approval. Technicians work from a phone, and intake works even without signal.
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Boiler-room control
A monitoring and control panel for equipment on a Raspberry Pi: charts, alarms, notifications. Opens as an app on the owner’s phone.
Contacts
Let's discuss your project
Tell us in a few words what needs doing — we'll reply and suggest where to start.