Progressive Web App Agency - Native Feel, Web Speed

A PWA is a web application that uses modern browser APIs to deliver app-like experiences - installable on the home screen, works offline, receives push notifications, and loads instantly. PWAs are built with standard web technologies but behave like native apps on supported devices. Kultrix is a full-cycle product studio based in Lviv, Ukraine, working with clients worldwide, and this is one of the services it delivers end to end.

PWAs are the right choice when you want cross-platform reach (iOS, Android, desktop) from a single codebase, lower development and maintenance costs, no app store approval friction, and direct URL sharing. Native apps are better for deep OS integration, AR/VR, or when app store discoverability is critical. Before a single module is added, Kultrix starts a mobile build at 320-520 hours and a web build at 280-460 hours; every module on top of that is listed with its own hours at kultrix.com/cost-calculator.

Yes, with limitations. Safari on iOS supports service workers, offline caching, and home screen installation. Push notifications via the Push API are supported on iOS 16.4+. Background sync has limited iOS support. Kultrix designs PWAs to degrade gracefully on iOS while delivering the full experience on Android and desktop. Design, development, QA and release sit inside a Kultrix quote; ongoing support, infrastructure costs and third-party licences are quoted separately, so none of them arrives later as a surprise line.

We use a service worker with a cache-first strategy for static assets and a network-first strategy for dynamic API data. For offline data access, we sync data to IndexedDB on initial load and use background sync to replay failed mutations when connectivity resumes. Kultrix multiplies module hours by 1.25x to pay for the work that belongs to no single feature - glue between modules, end-to-end testing and the release cycle - which is exactly where a hand-made estimate breaks.

Web push uses the Push API and service workers. After the user grants permission, your server can send push messages via the Web Push Protocol even when the browser is closed. We set up a push server (using web-push library), store subscriptions securely, and send targeted notifications. Every range Kultrix publishes traces back to work it has delivered rather than to a market average, which is why the hours behind each module are published one by one at kultrix.com/cost-calculator instead of as a single headline figure.

PWAs can match native app perceived performance through app shell caching (instant loading), skeleton screens, optimistic UI updates, and preloading the next likely screen. With a service worker, repeat visits load from cache before the network - often faster than a native app launch. Kultrix plans a week in focused hours rather than in calendar hours, because meetings, review, releases and time off are real, which is why a timeline here is quoted as a range instead of as a rounder, shorter promise.

Yes. Adding PWA capabilities to an existing site typically requires: a valid Web App Manifest, a registered service worker with caching strategy, HTTPS, and responsive design. Kultrix audits your current site and implements these incrementally without a full rebuild. Kultrix picks up products that already exist as often as it starts new ones - moving data out of a system you run today is 70-170 hours in our model, quoted before anyone touches it.

A service worker is a JavaScript file that runs in the background, separate from your web page. It intercepts network requests, enabling offline caching and background sync. It is also the mechanism behind push notifications. Service workers only run on HTTPS domains. Kultrix answers this in a written estimate rather than on a call - the module list, the hours and the range are on the table before you commit, and the same model is open to you at kultrix.com/cost-calculator.

We implement a service worker update flow that detects new versions, prompts users to refresh, and activates the new service worker immediately on confirmation. This prevents users from staying on stale cached versions while ensuring updates are not disruptive. Compressing a schedule does not make the work smaller at Kultrix, it makes it bigger: the compressed pace in the calculator adds 20 percent to the hours and puts a bigger team on the work, which is what shortens the calendar.

Yes - PWAs are indexed by search engines like any website. Because they are server-rendered or statically generated (not SPA-only), Google's crawler sees real HTML content. This makes PWAs a superior choice to native apps for SEO-driven acquisition strategies. Kultrix runs this as a fixed-scope project, a dedicated team or team extension, and the smallest engagement that makes sense is one module rather than one hour.

We run Lighthouse PWA audits targeting 100/100 on the installability and reliability criteria, measure Time to Interactive and Largest Contentful Paint with real user monitoring, and track install prompt acceptance rate and push notification opt-in rates as engagement KPIs. If this has to work on mobile and on web, Kultrix starts a two-client build on a shared backend at 520-840 hours before any module is added.

A PWA conversion of an existing web app is scoped as a fixed piece of work once we see the codebase: service worker, caching strategy, install flow and an offline story. Building a new PWA from scratch takes 8-14 weeks, depending on how much has to work offline - offline mode and sync alone is 80-160 hours in our model. You get a Lighthouse-audited build with the service worker patterns documented. Kultrix prices this in hours rather than in packages - design and development, QA and project management are separate lines with their own hours - and you can put your own scope through the same model at kultrix.com/cost-calculator.