Answer in brief
A mobile app is a program built to run on a phone or tablet and usually installed from a store such as App Store, Google Play or, in Russia, RuStore. It can be native, cross-platform, a web app or a PWA. Store apps pass a review and need updates; a site or PWA is often enough when customers come rarely.
A mobile app is a program that lives on the phone
When people ask what is a mobile app, the short answer is a program made for a small screen. Wikipedia describes it as an application designed to run on a mobile device such as a smartphone, tablet or smartwatch. The customer finds it in a store, installs it once and then opens it from an icon, without typing an address. That icon is the whole point: it keeps the business one tap away.
Most apps reach phones through stores. Wikipedia names Google Play for Android and the App Store for iOS among the biggest ones, and notes that Apple's store opened on July 10, 2008. In Russia there is also RuStore, a store for Android phones. Revenue from paid apps and purchases is usually split between the creator and the store, which is worth knowing before anyone plans to sell inside an app.
Native, cross-platform, web app and PWA compared
A native app is written for one operating system. Wikipedia defines native applications as designed specifically for a mobile operating system, typically iOS or Android. In practice that means two separate apps, two codebases and two teams or one team doing the work twice. In return you get full access to the phone: camera, sensors, notifications, payments, and the speed and look users expect from their own system.
A cross-platform app shares one codebase between iOS and Android. Flutter promises mobile, web, desktop and embedded experiences from a single codebase. React Native says its components render to native platform UI, so the app uses the same platform interfaces other apps do. Wikipedia also describes older hybrid apps, built with HTML, CSS and JavaScript inside a native container, and says they exhibit lower performance.
A web app runs in the browser and is not installed at all. Wikipedia notes it can be noticeably slower than the equivalent native app. A progressive web app, or PWA, sits between the two: web.dev, a guide for web developers, calls PWAs web apps built and enhanced with modern APIs, which can be installed and then open in their own window, from an icon on the home screen.
What a PWA can and cannot do instead of a store app
The strongest argument for a PWA is updates. The web.dev course on PWAs says users always get the latest version when they visit, with no packaging and no extra review. A platform-specific app, by the same course, usually ships as one indivisible package, and every update means re-packaging, re-signing, re-approval and re-installation on the device. For a menu, a price list or a booking form that changes weekly, this difference is real.
The limits are real too. Web.dev's own article admits that some capabilities are still out of the web's reach. Its PWA course says Apple's implementation misses many features other browsers have, lists integration APIs such as Web Bluetooth and WebNFC among them, and calls installation more of a challenge on iOS and iPadOS. Browsers change every year, so check the current state for the features you need before choosing.
How Apple reviews an app before the App Store
A store app does not go live when the code is finished. Apple's App Store Review Guidelines say every app is reviewed by experts. Section 2.1 asks for final versions with all metadata and working links, without placeholder text or empty websites, and warns that apps that crash or show obvious technical problems will be rejected. A demo for investors and a version for the public are therefore two different things.
Two rules surprise business owners most often. Section 4.2 says an app should offer features, content and interface that lift it beyond a repackaged website; a shop that simply wraps its site in an app risks rejection. Section 2.2 says demos, betas and trial versions do not belong on the App Store and should go through TestFlight, Apple's testing service, instead.
Money and data have their own rules. Section 3.1.1 requires in-app purchase when an app unlocks features or content, such as subscriptions or premium material. Section 5.1.1 requires a link to a privacy policy both in the store listing and inside the app. To publish at all, a company joins the Apple Developer Program, which its page lists as a 99 dollar annual membership at the time of writing.
Google Play and RuStore: accounts, testers and moderation
Google Play has a different entry gate. Play Console Help describes a one-time registration fee of 25 US dollars and an identity check that may ask for a government ID and a card under the legal name. For personal developer accounts created after November 13, 2023, it requires a closed test with at least 12 testers opted in for 14 days in a row before applying for production access. That review, Google says, usually takes seven days or less.
RuStore, which matters for the Russian market, describes three stages before publication: an automatic antivirus scan, manual moderation where specialists test the app, and a legal review that screens out law violations and banned content. Its help page adds that user complaints are reviewed by hand, and a confirmed violation can block the app and stop the developer from publishing new ones. Rules in all three stores change, so read the current version before planning dates.
When a business needs an app and when a site is enough
An app earns its place when customers come back often. A coffee shop with a loyalty card, a fitness club with a weekly timetable, a delivery service with repeat orders, a clinic with appointments and test results: in each case the icon on the screen saves the customer a search every time. The second reason is the phone itself, when the job needs the camera, geolocation, offline work or notifications that arrive reliably.
A site is enough when people come once or twice a year. A renovation company, a lawyer or a wedding venue gains little from an app nobody will open again, and every install costs effort the customer may not make. New customers still find such a company through search, and search leads to sites. For many small companies a fast mobile site is the first step, and the app question comes later.
A PWA is the middle path. It suits a catalogue, a booking flow or a personal account that regular customers use, when the needed features work in the browsers they actually have. It costs one codebase, needs no store review for each change and can still be installed. If later the business needs payments inside the app, deep phone access or a place in the store charts, the PWA becomes the prototype.
What goes into building and running a mobile app
Building an app is four pieces of work, not one. Design comes first: user scenarios, screens for both platforms, states for errors and empty lists. Then development of the app and, almost always, of a server part with an admin panel, because the app needs data from somewhere. Then publication: developer accounts, store listings with screenshots and descriptions, a privacy policy, test builds and answers to reviewers.
The fourth piece is the one budgets forget: support. Apple and Google release new system versions every year, store rules change, libraries age, and users report bugs from phones nobody tested on. Each store update passes review again, so even a small fix takes days rather than minutes. A realistic plan sets aside time and money for updates from the first month, not after the first crash.
Preparing to order a mobile app: MVP and scenarios
Start with the question behind what is a mobile app for your own company: which repeated action should become one tap. Write three to five scenarios in plain sentences, such as a returning client books a visit in under a minute. Mark which phone features each scenario needs, and which ones a browser could cover. That list decides between native, cross-platform and PWA better than any comparison table.
Then cut the first version down to an MVP: the smallest app that completes the main scenario and can pass store review. Prepare the content and accounts you own: texts, photos, prices, a privacy policy, developer accounts in your company's name. If you have a developer in-house, a PWA or a simple cross-platform app is a fair project to try yourself; when you order from a studio such as VITON13, bring those scenarios and get the scope and price in writing.
Practical checklist
- Write three to five user scenarios for the app in plain sentences, one action each.
- Mark which scenarios need the camera, geolocation, offline work or notifications.
- Check in current store rules whether your idea goes beyond a repackaged website.
- Register developer accounts in your company's name and prepare a privacy policy page.
- Plan a budget line for updates and store re-reviews from the first month after launch.
Questions and answers
How is a mobile app different from a mobile website?
A site opens in the browser by address and needs no installation. An app is installed from a store, lives as an icon and can use more of the phone, such as notifications, sensors and offline work. A site is found in search; an app is found in the store or through your site.
Is a cross-platform app worse than a native one?
Not by default. Frameworks such as React Native render native interface elements, and one codebase cuts the work for two platforms. Native code still wins when an app leans heavily on new system features, complex graphics or deep hardware access.
Can a PWA be published in the App Store or Google Play?
The web.dev course says a PWA can be listed in app stores as an optional channel, including Google Play, Microsoft Store and the App Store, but it must then follow each store's rules. Apple's guideline against repackaged websites applies here too.
How long does store review of a new mobile app take?
Apple's guidelines do not promise a fixed time. Google says the review for production access usually takes seven days or less, after a 14-day closed test for new personal accounts. Plan at least a few weeks between a finished build and the public release.
Does a small business need its own mobile app?
Only when customers return often enough to keep an icon on their phone, or when the service needs phone features a browser cannot give. Otherwise a fast mobile site or a PWA brings the same orders for less money and less upkeep.