Mobile App Design Process in 2025: The 12‑Step Playbook to Design

9 Min Read

Design

Mayursinh Jadeja

Aug 18, 2025

In this blog post

Introduction

If your roadmap still feels like a guessing game, you’re not alone. iOS 18 patterns, Android 15 updates, stricter store reviews, and rising expectations around privacy and accessibility have made shipping a polished app harder—and riskier—than ever. Teams burn cycles on rework, handoff ambiguities, and last-minute compliance issues.

This guide lays out the mobile app design process in 2025 from brief to handoff so you can move decisively. We design only—we do not develop apps. We collaborate with your in-house or partner engineering team to ensure a clean, unambiguous handoff that accelerates implementation. You’ll see how Redlio Designs structures discovery, translates insights into user flows and prototypes, crafts platform-aware design systems (SwiftUI/Compose), and hands off dev-ready files that reduce ambiguity. We’ve also bundled checklists for accessibility, privacy, and performance—and real examples showing how these practices cut rework and drive outcomes. By the end, you’ll have a repeatable playbook: what to do in each phase, which artifacts to expect, how to control scope, and where 2025 platform trends change the way you design.

Why Redlio Designs in 2025: Future-Ready, Engineering-Aligned

Future-ready means today-ready. At Redlio, we design on current platform patterns (iOS 18, Android 15) and deliver designs with accessibility and privacy guardrails baked in. Our philosophy is simple: outcomes over outputs. Every phase maps to measurable improvements—activation, task success, or rework reduction—so you know what you’re buying.

What consistently goes right when you work this way:

Less rework: A shared token system and clear variant states slash visual diffs across iOS/Android.
Faster milestones: Specs, redlines, and interaction notes eliminate “what does this do?” threads.
Smoother reviews: Early compliance checks (permissions, data use, screenshots) prevent last-mile surprises.

The Redlio Standard (you always receive):

Phase-wise owner checklists and sign-off gates
Decision log (what changed and why) and a change-request policy
Token matrix (iOS ↔ Android), component documentation, redlines/specs
Accessibility acceptance criteria and a pre-submission compliance checklist

Actionable next step: In your kick-off, align on what “good” looks like. Capture business KPIs (e.g., onboarding completion, task success rate, handoff cycle time) and tie them to phase outcomes. That anchor keeps work focused when scope pressure arrives.

Phase 0–1: Brief → Discovery & Strategy

Strong discovery prevents most downstream rework. We start by framing the right problem and defining success before opening Figma.

Context (2025 realities): feature lists multiply quickly, stakeholders are distributed, and platforms introduce new constraints (consent, identity, gestures). Without early alignment, teams greenlight features that don’t move KPIs—or stall in review.

How we do it:

Problem framing & KPIs: Translate goals into measurable outcomes (e.g., “increase Day-7 activation by 15%”).
Stakeholder & user interviews: Jobs-to-be-done, pain points, motivations; identify risky assumptions to test.
Analytics & heuristics review: Baselines for funnels, task success, and drop-offs; quick wins list.
Competitive & pattern scan: Note relevant iOS 18/Material 3 patterns to leverage rather than reinvent.
RACI & guardrails: Who decides what, by when; change-request policy to prevent scope drift.
Risk register: Privacy, offline usage, device fragmentation, legal/regulatory concerns.

Artifacts you should expect: discovery brief, persona snapshots, hypothesis list, measurement plan, and a one-page strategy linking problems → bets → success metrics.

Actionable takeaway: Before committing to UI, agree on 3–5 testable hypotheses (e.g., “reducing KYC steps by one increases completion by 10%”) and design prototypes to validate them. This keeps later debates data-anchored.

Phase 2: Information Architecture & User Flows

Flows are where product risk becomes visible. We model primary journeys (signup, search, purchase, onboarding) and edge cases (timeouts, permissions denied, low network) so implementation surprises disappear.

Context (2025 realities): deeper OS privacy prompts, evolving sign-in methods (passkeys/one-tap), complex deep linking, and multi-device continuity. Teams that skip edge flows pay for it in QA.

How we do it:

IA vs. sitemap: Establish structure and content domains before screens balloon.
Primary flows: For each goal, define a happy path + critical branches.
Error/exception mapping: Offline states, retries, rate limits, expired sessions.
Permission strategies: When/where to ask, rationale copy, and fallback UX.
Versioning & governance: Flow IDs, change logs, and owners; keep flows and prototypes in sync.

Artifacts you should expect: annotated flow diagrams, state charts for complex domains, and an edge-case checklist tied to acceptance criteria.

Actionable takeaway: Set a sign-off gate here. No wireframes until flows are validated against KPIs and edge cases. It’s cheaper to change arrows than screens.

Phase 3: Wireframes → Interactive Prototypes

Fidelity is a tool, not a goal. We move from low-fi to mid-fi with just enough precision to answer the question at hand.

Context (2025 realities): stakeholders often mistake polished visuals for validated UX. Prototypes should test hypotheses, not just aesthetics.

How we do it:

Wireframe taxonomy: Low-fi for structure and IA; mid-fi for interactions and content priority.
Interactive prototypes: Hotspots, transitions, gestures, and haptic notes where appropriate.
Microcopy & empty states: Clear guidance for permissions, errors, and data-sparse moments.
Hypothesis tagging: Each flow element traces to a hypothesis and metric.
Review setup: Short, task-based demos to avoid “design by committee.”

Artifacts you should expect: prototype links, task scripts, a prototype acceptance checklist (what must be testable), and a decision log that records what we learned and changed.

Actionable takeaway: Timebox feedback cycles (e.g., 48–72 hours) and structure comments by goal, concern, suggestion to keep reviews constructive and traceable.

Phase 4: Design System & Visual Design (SwiftUI + Compose)

Tokens are the contract between design and code. They carry the brand from Figma into implementation without drift.

Context (2025 realities): two platforms, one brand; adaptive layouts, dark mode, dynamic type, and localized content are the norm. Visual parity without token discipline leads to QA churn.

How we do it:

Foundation tokens: Color, typography, spacing, radii, elevation, motion.
Components: Buttons, nav bars, sheets, cards; state and variant matrices (hover/focus/pressed/disabled, success/warn/error).
Platform specifics: iOS 18 patterns, SwiftUI stacks/navigation; Android 15’s Material 3 + Compose, adaptive layouts.
Accessibility baked in: Contrast, dynamic type, focus order, reduced-motion preferences.
Governance: Naming conventions, versioning, contribution rules, and change logs.

Artifacts you should expect: token matrix (iOS ↔ Android), component library, redlines/specs, interaction notes, and a visual QA checklist.

Actionable takeaway: Freeze a v1.0 design system before broad visual polish. Lock tokens and core components so downstream work scales without surprise deltas.

Phase 5: Usability Testing, Accessibility & Iteration

Testing isn’t a checkbox—it’s your quality engine. We validate whether users understand the UI and can complete tasks quickly and confidently.

Context (2025 realities): heightened accessibility expectations, voice and larger dynamic type adoption, and legal exposure for inaccessible experiences.

How we do it:

Task-based tests: Remote/moderated, 5–7 participants per round; measure task success, time on task, error rate.
Accessibility checks: Labels, contrast, focus order, screen reader flows, motion preferences.
Insight logging → iteration: Tag findings as ship/fix/park; cadence for iteration and retest.
Performance sensitivity: Motion budgets, image formats, network constraints for emerging markets.

Artifacts you should expect: test plan, script, recordings (where permitted), findings matrix, and acceptance criteria (e.g., “≥85% task success on core journeys”).

Actionable takeaway: Include accessibility and performance acceptance criteria in Definition of Done so they can’t slip under launch pressure.

Phase 6: Dev Handoff & Pre-Launch Compliance

“Dev-ready” means zero ambiguity. Handoffs must be unambiguous for implementation—no guesswork.

Context (2025 realities): stricter store policies, privacy expectations, and media requirements create last-mile friction when handled late.

How we do it:

Figma → engineering: Clean page structure, named frames, component docs, redlines/specs, interaction notes.
Token export: Mapped to SwiftUI/Compose variables; theming rules documented.
Pre-submission checklist (advisory): App metadata, screenshots, permission rationales, privacy disclosures, telemetry minimization.
Release rehearsal (advisory): Dry run to surface gaps—especially around identity, payments, and permissions. We guide your team; your developers own the submission.

Artifacts you should expect: handoff package (Figma links + docs), token exports, compliance matrix, and a submission readiness audit.

Actionable takeaway: Book review windows before final handoff. Align product, design, legal, and engineering on a cut-off date so you’re not polishing screenshots the night before submission.

Case Studies

Case Study A — Fintech Onboarding

Problem: KYC friction caused users to abandon onboarding at the document step.
Intervention: Reduced steps from 5 → 4, clarified document guidance, added progress cues; adjusted permission prompts to appear contextually.
Result: +19% completion, −23% time-to-complete, no review delays.

Case Study B — Two-Sided Marketplace

Problem: Visual drift between iOS and Android created QA churn.
Intervention: Introduced a shared token matrix and component parity checklist; redlined interaction states.
Result: −27% rework in QA, −18% handoff cycle time, faster cross-platform alignment.

Case Study C — Wellness App

Problem: Users failed to discover routine setup.
Intervention: Simplified flows, improved empty-state microcopy, added accessible navigation cues and haptics.
Result: +32% task success, +14% Day-7 activation.

FAQs

Q1. What are the exact phases and sign-off gates?
A. Discovery/Strategy → IA & Flows → Wireframes/Prototypes → Design System & Visual Design → Testing/Iteration → Handoff & Compliance. Each phase ends with: owner checklist, decision log, and explicit sign-off criteria.

Q2. How do IA, flows, and wireframes connect?
A. IA defines structure; flows model behavior; wireframes visualize screens for those behaviors. We validate flows before drawing screens to prevent late changes.

Q3. What’s different in 2025 for iOS/Android patterns?
A. iOS 18 and Android 15 push native gestures, adaptive layouts, and stricter permission patterns. Design systems must encode these conventions to avoid rejection risks and UX inconsistency.

Q4. What does a dev-ready handoff include?
A. Clean Figma structure, specs, interaction notes, token exports mapped to SwiftUI/Compose, and a submission checklist (privacy, metadata, screenshots).

Q5. How do we control scope creep?
A. RACI assignments, change-request policy, and hypothesis-driven prototyping. If a change doesn’t serve the KPI, park it.