Introduction to Mobile development

Mobile development allows you to put software that interacts with both the humans and the physical world in the hands of almost everyone in the world.

This type of development involves working with mobile platforms, most commonly iOS OS and Android OS, which are pretty capable platforms having many features in a compact and easy-to-carry format that almost everyone in the world has access to. Building mobile apps allows to distribute software that can interact with users as well as the physical world trough the phone’s sensors.

Characteristics

User-centric: Building mobile apps is all about the user experience, expectations on performance and UI. But it also allows you to interact with the device’s features, like notifications, widgets, other apps installed or GPS, Camera, etc.
Resource limitations: Mobile platforms are constrained environments, both on CPU and Battery, that’s why each platform allow some kind of interaction with the lifecycle of your process to execute work where it matters the most and not waste resources on things that the user won’t use.
Offline and Online functionality: Although most apps use or rely on the network, mobile apps have a core difference from i.e. Web development, where internet connection is expected. In the mobile world, the user can or can’t be connected or can even transition between different network statuses. That’s why in the mobile world network errors are expected and should be handled without harming UX.
Security and data protection: Having access to such powerful device on everybody’s pocket also opens up a lot of security implications, that’s why in the mobile world it is required to be transparent about the usage of certain features trough permissions which are presented to the user, your app should handle scenarios where certain feature is disabled or the user doesn’t want to allow your app access to that specific feature.
Platform updates: Mobile Operating systems go under constant updates, which change how your app works on the each newer version, forcing you as a developer to keep up-to date with the changes, update your app and test with newer to ensure backwards-compatibility.
Stores: Although Stores are optional in some platforms like Android, they are the main distribution channel where most users have access and go to. These stores have acceptance criteria which determines wether or not your app is allowed on their store. This usually requires having a developer account, that usually has a cost and having some marketing material to show off your app in their store is needed.
App updates: Once an app published, it usually requires updates, wether bugfixes, security or new features, these updates need to get to the app’s users. This is done by producing a new binary and distributing it, usually, trough a store, which will take some time to review it, and even when approved, the users will take some time to update the app (or they can even never update it). This makes iterations in mobile apps really slow.

Do you really need a mobile app?

Why you might need an app

Convenience: Ideal for quick every day tasks that a user will want to access frequently, even in short windows of time.
Offline access: Does your product needs offline functionality
Hardware access: If your product requires specific hardware access (that might not be supported by the browser) a mobile app might be needed.
Core to business: If an app is core to your business model

Why you might not want an app

Development & Maintenance cost: Mobile apps are considerably more expensive, since it usually involves at least two platforms (meaning two codebases) and having to maintain the app updated and tested with the lates OS releases.
Limited use case: If users do not need frequent interaction or device features, a simple website or web app is often more practical
Alternative Solutions Exist: If a website provides everything users need, an app may add little value and risk being redundant
User Demand Uncertainty: There’s fierce competition with millions of apps—users download few, so new apps may struggle to gain traction

Comparison between other platforms

Characteristics	Mobile	Web	Desktop
Access to Device Features	Full access (camera, GPS, sensors, notifications)	Limited, via browser APIs	Full access to hardware and peripherals
Offline Functionality	Often designed for offline use and sync	Limited offline support (via PWA technologies)	Full offline capability
User Engagement	Push notifications, integrated with device	Email alerts, limited push notifications	Limited direct engagement tools
Development Cost	Often higher due to multiple platforms and app store compliance	Lower, single codebase for all platforms	Medium to high, depending on platform and complexity
Installation & Distribution	Installed via app stores	No installation needed, accessed via URL	Installed locally on the system
Platform Dependency	Platform-specific (iOS, Android) with native SDKs or cross-platform tools	Platform-independent (runs in browsers)	Platform-specific (Windows, macOS, Linux)
Development Complexity	Requires knowledge of platform-specific languages or cross-platform frameworks	Uses standard web technologies (HTML, CSS, JS)	Uses platform-specific languages and frameworks
Update Process	Updates through app stores, user-dependent	Instant updates for all users	Updates need manual installation or auto-update setup
Security	High focus on data protection, platform-enforced security	Depends on web security practices	High security with OS-level protections

Native Development

Android Development MOC
iOS Development MOC

Cross-Platform

Progressive Web Apps
ReactNative
Kotlin Multiplatform
Compose Multiplatfrom
Flutter