Most people imagine a mobile app is built the same way as a website, only more complicated. The reality is different, and understanding the process will help you work far better with your provider, avoid costly misunderstandings, and ship a better product.
Step 1: Defining the product
Before writing a single line of code, you need to answer three questions: who uses the app, in what context, and to achieve what? This phase sounds simple, it's actually the most important step of all. Apps that fail almost always fail because these questions were answered badly, not because of technical bugs.
The deliverable for this phase is a specification document: a prioritised list of features, each with a description of the target user and the goal it serves.
Step 2: UX design (wireframes)
Wireframes are greyscale mock-ups, with no colours or images, just the structure. The aim is to validate the user journey before spending time on the visual design. It's far cheaper to change the position of a button at this stage than after development is finished.
Step 3: UI design (the real look)
This is where your app comes to life visually: colours, typography, icons, animations. This step produces an interactive prototype, a simulation of the app that you can test on a real phone before development begins. It's your last chance to easily change anything that doesn't feel right.
Step 4: Development
Developing a mobile app splits into two parts: the frontend (what the user sees and touches) and the backend (the servers, the databases, the business logic). For a simple app, development can take 2 to 4 months. For a complex one, 6 to 12 months.
At this stage, interim builds are shared with you regularly so you can test them and give feedback. Don't go weeks without seeing the product evolve.
Step 5: Testing
An app that hasn't been tested on real devices is an app that's going to break in production. Testing covers functionality (does it work?), performance (does it work quickly?), and compatibility (does it work across different devices and OS versions?).
Step 6: Publishing
Publishing to Apple's App Store or the Google Play Store isn't instant. Apple can take anywhere from 24 hours to several days to review your app. Plan accordingly: don't promise a launch date without allowing for this delay.
Building a mobile app is a serious undertaking, but a manageable one if you know what to expect at each stage. The secret to a successful launch is almost always the same: good communication throughout the process, and decisions made early rather than late.