What you get
Scope depends on the project, but full app design usually includes:
- a screen map and descriptions of key flows: sign-up, search, checkout, booking, payment;
- a clickable Figma prototype you can tap through on your phone;
- mockups of every screen for iOS and Android, in light mode and, if needed, dark mode;
- a UI kit: colors, fonts, icons, buttons, fields, and cards with all their states;
- behavior specs: animations, transitions, error messages, empty states;
- an app icon and graphics for your App Store and Google Play listings.
Everything lives in a single Figma file, organized so a developer can find the right screen or component without asking the designer. Smaller projects have a smaller scope — for example, just a prototype for investors or a redesign of a few key flows.
Who needs custom app design
Custom design pays off when the app is an important sales or service channel: customers place orders, manage subscriptions, or book services in it. Here, every extra step or confusing button directly costs you customers.
For an internal tool used by a few dozen employees, on the other hand, full branded design is often overkill. Well-thought-out flows and standard iOS or Android elements are enough: it costs less, and users immediately understand how everything works. We'll tell you upfront if that's your situation.
Platform guidelines: iOS and Android
Apple and Google publish their own design guidelines — the Human Interface Guidelines and Material Design. They describe how navigation, menus, buttons, and dialogs should look and behave. Even users who have never heard of these rules can tell when an app doesn't follow them.
The platforms differ in many ways: going back with an edge swipe on iOS versus the system back button on Android, different toggles, date pickers, and menu placement. There are two approaches:
- adapting to each platform — more familiar for users, but design and development take longer;
- one unified brand style — easier to maintain, especially for cross-platform apps, though critical navigation elements should still feel familiar.
In practice, we usually land in the middle: a shared brand style, with platform conventions where they matter.
We also pay close attention to accessibility: sufficient text contrast, proper support for larger system font sizes, and labels for screen readers used by people with visual impairments. We follow WCAG recommendations and the platforms' own requirements.
Full custom design, design based on system components, or a redesign
- Full custom design from scratch — from research and user flows to a UI kit. Best for new products and apps where the interface is a competitive advantage. The downside: it's the largest scope of work.
- Design based on system components — we design the flows and build screens from standard platform elements in your colors and fonts. Faster and more affordable, and a good fit for a first product version or internal apps.
- Redesign — an update of an existing app. We start with analytics and reviews to understand exactly what's getting in users' way, then change the interface in stages.
What to prepare before we start
- a product description: who it's for, what problem it solves, how it makes money;
- your brand identity, if you have one: logo, colors, fonts;
- a few apps you like or dislike, and why;
- for a redesign: analytics data, user reviews, support tickets;
- development constraints: what the app is built with and what's already been implemented.
If you don't have some of this, that's fine: we'll work out the missing answers together during the briefing.
How we make sure the design works
Before development, on the prototype. We give a few people from your audience specific tasks ("find a product and place an order") and watch where they hesitate or make mistakes. Just a handful of these sessions show where the interface confuses people.
After launch, with data. Together with the developers, we set up analytics for key flows: how many people complete sign-up, at which step they abandon checkout, and which features hardly anyone uses. That becomes the basis for the next round of improvements.
Common app design mistakes
- Porting a website into an app. Menus, long text, and tables that work on a computer get in the way on a phone.
- Designing only the "ideal" screens. Without loading, error, and empty states, developers make them up on their own — and the app feels unfinished.
- Tiny controls. Buttons that are hard to hit with a finger and text that's hard to read on the go.
- Requiring sign-up on the first screen. Many people delete the app before they ever see what it can do.
- Designing without developers. Decisions that are hard or expensive to build only surface during development.
What affects the cost
- The number of flows and screens, plus user roles if there are several: customer, courier, admin.
- Research depth: competitor analysis, interviews, prototype testing with users.
- Platforms: one style for all, or separate adaptations for iOS and Android, tablets, and dark mode.
- Animations and illustrations created specifically for the app.
- Existing brand identity: if you don't have one, the visual language will need to be developed.
Frequently asked questions
Can I order just the design and have my own team handle development? Yes. We hand over the mockups, UI kit, and behavior specs, and can consult your developers as needed.
How is app design different from website design? Different usage scenarios, gestures, platform guidelines, notifications, and offline behavior. We cover general usability design principles on our UI/UX design page.
What software do you use? Figma: mockups, prototypes, and components live in one file that both you and your developers can access.
Do I need a separate design for tablets? If people actively use your app on tablets, yes — otherwise the interface will look like a stretched-out phone.
Can you help with design if the app is already in development? Yes. We can join the project at any stage: review existing mockups, design missing states and screens, and pull scattered elements together into a single UI kit.
Why Promodex
Our agency has been in business since 2015, with 750+ projects and 50+ awards. Our portfolio includes Zoomerang and Kinodaran, as well as Komoot and Too Good To Go, which we contributed to. Designers and developers work on the same in-house team, so mockups account for development realities from day one, not just aesthetics. We never outsource the work, and we stay with you as the app keeps growing after launch.
