How to Design an iPhone App: 8 Rules for Non-Designers (2026)

By Sigsten Gustavii· 27 October 2026· 8 min read

To design an iPhone app, decide the one job of each screen, use the navigation iPhone owners already know, let the system handle text size and dark mode, pick one accent colour and one type style, use Apple's icons, and test the result on a real phone at arm's length. With a native builder like Borel, most of Apple's rules come for free; your job is taste and clarity.

Most bad app design is not ugly; it is confusing. A screen does three things at once, buttons hide behind unfamiliar icons, text is too small for half the people using it. The good news is that Apple has already solved most of this, in its Human Interface Guidelines and in SwiftUI. A native app that follows them looks at home on the iPhone with very little effort.

Rule 1: One job per screen

Before colours and fonts, decide what each screen is for. The home screen of a habit app shows today's habits and lets you tick them. That's it. Settings, history and statistics live one tap away. If you can't say a screen's job in one sentence, split it.

Rule 2: Use the navigation people already know

On iOS 26, SwiftUI's tabs become the floating Liquid Glass tab bar automatically, and on earlier iOS the classic one; see Liquid Glass. Custom navigation rarely beats these; people know how they work before they open your app.

Rule 3: Let text scale

iPhone owners choose their text size in Settings, and many choose larger. Apple's typography guidance asks apps to support Dynamic Type. In a Borel app, every size that holds text grows with the reader's setting, headings and big numbers included. Design layouts that wrap rather than truncate, and check the largest size before you publish.

Rule 4: Design for dark mode

Dark mode is not an inverted colour scheme; it is a second palette. Apple's dark mode guidance recommends system colours that adapt. Borel gives every custom colour a dark-mode version, or commits to a dark look on purpose when that suits the app, so text stays readable either way.

Rule 5: One accent colour, one type style

Calm apps use colour sparingly: a neutral background, plain text, and one accent colour for what you can tap or what matters most. Pick one type style for the whole app, such as Apple's default, a rounded design for a playful app, or a serif for a journal. Before the opening build, Borel weighs four visual directions for your app and commits to one; if you name a look, yours wins.

Rule 6: Make everything easy to tap

Apple's layout guidance recommends touch targets of at least 44 by 44 points. Put the most-used actions within reach of a thumb, near the bottom of the screen, and keep destructive actions away from frequent ones. Native SwiftUI controls are already sized for touch; trouble usually comes from tiny custom icons.

Rule 7: Use Apple's icons

SF Symbols are Apple's own icon set, thousands of symbols that match the system font and scale with text. A native app uses them by default, so a trash can, a plus or a share icon means the same thing in your app as everywhere else on the iPhone. Pair an icon with a word wherever its meaning could be unclear.

Rule 8: Design with real content

Lorem ipsum hides problems. Long names, empty lists, a year of data, a missing photo: real content shows where a design breaks. Borel apps open with a few starter rows you can edit or delete, so the app shows what it does from the opening screen, and Borel's building blocks include an empty state for lists with nothing in them yet. Apple also rejects apps with placeholder text under Guideline 2.1, so this rule pays twice.

Accessibility is design

Designing for accessibility makes an app better for everyone. Native SwiftUI apps work with VoiceOver, Apple's screen reader, as long as every button has a clear label; an icon-only button needs a spoken name like "Add expense". Don't rely on colour alone to carry meaning: pair red and green with a word or a symbol. Keep contrast high enough to read outdoors. And respect Reduce Motion: a calm fade instead of a big animation for people who turn motion down. Borel's apps follow the system settings for text size and dark mode, and you can ask for the rest in plain words.

A design checklist before you publish

• Every screen's job fits in one sentence.
• The tab bar has three to five items, each with an icon and a word.
• The largest text size still reads without overlaps.
• Dark mode reads everywhere, including charts and photos' captions.
• Every button is easy to hit with a thumb.
• Empty lists explain what will appear and how to add the opening item.
• No placeholder text or "coming soon" anywhere.
• The app icon is simple and readable at small size.

Apple's Guideline 4.2 turns down apps that don't feel like real apps, and 4.1 turns down copies of famous apps. A clear, native design with its own look helps with both. See App Review in the glossary.

How to choose the right way to design an app

• Borel, if you want native SwiftUI design by default, a visual direction chosen for your app and changes in plain words.
• A design tool, if a designer will draw every screen before anything is built.
• Xcode and SwiftUI by hand, if you are a developer who wants full control over every detail.
• [FlutterFlow](/compare/flutterflow) or other cross-platform builders, if you need Android too; their components imitate iOS rather than using it.

How to do it with Borel, step by step

Step 1: Describe the feel along with the features

Make a reading tracker. It should feel calm and bookish: a warm paper background, a serif font, one deep green accent, and lots of space. Tabs for Reading now, Finished and Stats. Big book covers in the lists. Respect large text sizes and make dark mode feel like reading by lamplight.

Borel's planner, Penny, asks about anything unclear and weighs four visual directions; your words decide. Rivet writes the app in SwiftUI, and Borel looks at the built opening screen once to polish what it sees.

Step 2: Look at it on a live iPhone

In the iOS Simulator in your browser, switch to dark mode and the largest text size, and tap through every tab.

Step 3: Change what you see in plain words

"Make the covers bigger", "less bold on the headings", "move Add to a floating button at the bottom right". Every change is built again and every version is kept, so you can roll back.

Step 4: Check it in your hand

With Pro, install it on your iPhone with Borel Companion and use it with one hand, outdoors and at night.

Step 5: Publish

Stamp checks the app, and Publish builds and uploads it under your Apple Developer account. More on native design.

The Bottom Line

You don't need to be a designer to make an iPhone app that feels right. Give each screen one job, use the navigation people know, let text scale, plan for dark mode, keep one accent and one type style, make things easy to tap, use Apple's icons and design with real content. Native SwiftUI does much of it for you, and Borel adds a look of its own. Describe the feel of your app on Borel and look at it on a live iPhone.

I think most bad app design is confusion, not ugliness. Give each screen one job and let SwiftUI do the rest.

– Sigsten

Make your iPhone app in Borel

Describe the app you want and see its first screens before you pay anything.