Introduction

Building a great app is not enough. With over 2 million apps on each major store, discovery is the real challenge. App Store Optimization (ASO) is the practice of improving your app’s visibility in store search results and browse sections.

Unlike paid acquisition, ASO delivers compounding returns. Every optimization you make continues working as long as your app exists. For most apps, organic search drives the majority of installs.

This guide covers ASO fundamentals that every app developer should understand.

How App Store Discovery Works

iOS

App Store

Apple’s App Store ranks apps based on:

Relevance: How well your metadata matches the search query
Performance: Downloads, ratings, reviews, engagement
Recency: Recent updates may receive temporary boosts
Category: Performance relative to category peers

The App Store emphasises editorial curation. Featured placements can drive massive downloads but are unpredictable and uncontrollable.

Search accounts for roughly 65-70% of App Store downloads. The remaining comes from browsing, referrals, and external sources.

Google Play Store

Google Play uses similar signals with some differences:

Relevance: Metadata matching with broader text analysis
Performance: Installs, ratings, reviews, uninstall rate
Engagement: How actively users engage after installing
Backlinks: External links to your Play Store listing

Google’s algorithms feel more SEO-like, incorporating signals beyond explicit metadata. Description text, developer responses to reviews, and external mentions may influence rankings.

Search drives approximately 50-60% of Play Store downloads, with browsing and recommendations playing a larger role than on iOS.

Keyword Research

Keyword Research Infographic

Understanding Search Intent

Users search with different intents:

Brand searches: “Instagram,” “Spotify”—already know the app
Category searches: “photo editor,” “budget tracker”—exploring options
Problem searches: “remove background from photo,” “split bills with friends”

Brand searches are difficult to rank for unless you are the brand. Category and problem searches offer opportunities.

Finding Keywords

Start with brainstorming:

What does your app do? (category keywords)
What problems does it solve? (problem keywords)
What would you search for? (natural language)
What do competitors rank for? (competitive analysis)

Then validate with tools:

App Annie: Search rankings, competitor analysis Sensor Tower: Keyword difficulty scores, suggestions Mobile Action: Keyword tracking, ASO intelligence AppTweak: Keyword research, competitor benchmarks

Free alternatives include Google Keyword Planner (indicates general search volume) and App Store/Play Store autocomplete suggestions.

Evaluating Keywords

For each keyword, assess:

Factor	Question
Volume	How many people search this?
Difficulty	How competitive is this keyword?
Relevance	Does this match what your app does?
Intent	Are searchers likely to download?

High volume + high relevance + manageable difficulty = target keyword.

Avoid vanity keywords with massive volume but low relevance. Ranking for “free games” does not help if you built a meditation app.

Long-Tail Strategy

Specific phrases are easier to rank for:

“photo editor” = extremely competitive
“photo editor remove background” = competitive
“photo editor remove background free” = achievable

Long-tail keywords have lower volume but higher conversion. Users searching specific phrases know what they want.

Metadata Optimization

Metadata Optimization Infographic

App Name/Title

Your app name is the strongest ranking signal. Include your primary keyword if possible while maintaining brandability.

iOS: 30 characters maximum Android: 30 characters maximum

Examples:

“Headspace: Meditation & Sleep”
“Mint: Budget & Expense Tracker”
“Canva: Graphic Design Creator”

The pattern: [Brand]: [Primary Keywords]

If your brand is unknown, lead with keywords:

“Budget Tracker - Expense Manager”

As brand recognition grows, you can rebalance toward the brand.

Subtitle (iOS) / Short Description (Android)

This secondary text field provides additional keyword opportunities.

iOS Subtitle: 30 characters Android Short Description: 80 characters

Use different keywords than your title to maximise coverage:

Title: “PhotoFix: Edit & Retouch” Subtitle: “Remove Backgrounds Easily”

Keywords Field (iOS Only)

Apple provides a 100-character keyword field, invisible to users. This is pure SEO territory.

Optimisation tips:

Use commas to separate keywords
Do not repeat words from your title
Include common misspellings
Use singular or plural, not both (Apple matches both)
Include competitor brand names (controversial but common)

Description

Play Store descriptions influence rankings. iOS descriptions do not directly affect search but influence conversion.

For both stores:

Lead with benefits, not features
Front-load important keywords (first few lines visible without expansion)
Use bullet points for scanability
Include a clear call to action
Update with new features and improvements

Category Selection

Choose the most relevant category. Being a small fish in the right pond beats being invisible in the wrong one.

If your app fits multiple categories, pick the one with the best competitive landscape. A meditation app might perform better in Health & Fitness than Lifestyle, depending on competition.

Visual Optimization

App Icon

Your icon appears in search results, category listings, and home screens. It must work at tiny sizes and stand out among competitors.

Best practices:

Simple, recognisable silhouette
Limited colour palette (2-3 colours)
Avoid text (unreadable at small sizes)
Consistent with your brand
Distinct from competitors

Test your icon against competitors. Place it in a lineup of search results. Does it stand out?

Screenshots

Screenshots are your primary conversion tool. Most users decide based on screenshots alone, never reading the description.

iOS: Up to 10 screenshots per device type Android: Up to 8 screenshots

Effective screenshot strategies:

Benefit-focused captions: Not “Home Screen” but “Track Spending in Seconds”
First two screenshots matter most: These appear without scrolling
Show real UI: Users want to see what they are getting
Consistent style: Unified design language across all screenshots
Localise for markets: Australian dollars in Australian store

Screenshot types that work:

Feature highlights with caption overlays
Before/after comparisons
Social proof (user counts, ratings)
Process walkthroughs

Preview Videos

Both stores support app preview videos. Videos auto-play in the App Store (muted), making them high-impact.

Video best practices:

15-30 seconds maximum
No sound dependence (assume muted playback)
Show real app usage, not conceptual animations
Front-load the most compelling content
End with a call to action

Videos require more effort but consistently improve conversion rates.

Ratings and Reviews

Why Ratings Matter

Ratings affect both rankings and conversion:

Apps below 4.0 stars struggle to convert
Each half-star improvement can increase conversion 5-10%
Rating velocity (recent ratings) may influence rankings

Getting More Ratings

iOS and Android provide native rating prompts (SKStoreReviewController and In-App Review API). These are less intrusive than custom prompts and often yield better results.

Timing matters:

Ask after positive moments (completed task, achievement unlocked)
Do not ask during onboarding
Do not ask too frequently (iOS limits to 3 prompts per year)
Do not ask after frustrating experiences

Some apps ask “Are you enjoying [App Name]?” first:

Yes → Show native rating prompt
No → Route to feedback form (avoid negative rating)

This pattern is effective but borderline against store guidelines.

Responding to Reviews

Responding to reviews demonstrates engagement:

Thank positive reviewers
Address concerns in negative reviews
Provide helpful information (support links, workarounds)
Be professional always

On Play Store, responding to reviews may influence rankings and shows potential users you care about feedback.

Localisation

High-Impact Markets

English is competitive. Localising metadata can dramatically improve performance in other markets.

Priority markets by spending:

United States
Japan
United Kingdom
Australia
Germany
France
South Korea
Canada

Localisation does not mean translation. Research keywords in each language—direct translations often miss how local users actually search.

What to Localise

Minimum:

App name/title
Subtitle/short description
Keywords
Screenshot captions

Full localisation:

All metadata
In-app content
Support documentation

Start with metadata localisation. It requires less effort than full in-app localisation but captures significant value.

Measuring ASO Performance

Key Metrics

Track these metrics over time:

Metric	What It Tells You
Impressions	How often your app appears in search
Product page views	How often users view your listing
Conversion rate	Page views → Downloads
Keyword rankings	Positions for target keywords
Downloads	Total and organic downloads

Both App Store Connect and Google Play Console provide these metrics.

A/B Testing

Google Play Console offers built-in A/B testing for:

Icons
Screenshots
Descriptions
Short descriptions

Apple recently introduced product page optimization in iOS 15, but as of early 2021, testing on iOS requires third-party tools or before/after analysis.

Test one element at a time. Run tests for statistical significance (typically 7+ days, thousands of impressions).

Common ASO Mistakes

Keyword Stuffing

Cramming keywords unnaturally hurts both rankings and conversion:

Bad: “Photo Editor Photo Editing Edit Photos Photo Collage Photo Filter” Good: “PhotoFix: Edit & Retouch Photos”

Stores penalise obvious stuffing. Write for humans who are searching, not algorithms.

Ignoring Competitors

Your rankings are relative to competitors. If a competitor improves their ASO, your relative position drops even if you change nothing.

Monitor competitor listings:

What keywords are they targeting?
What do their screenshots emphasise?
How are their reviews?

Set and Forget

ASO is not a one-time activity. Revisit and refresh:

When adding features
When competition changes
When seasonal opportunities arise
Quarterly at minimum

Store algorithms evolve. User search behaviour changes. Continuous optimisation maintains and improves rankings.

Neglecting Conversion

Rankings without conversion waste impressions. Optimise the full funnel:

Impressions → Page views → Downloads

Beautiful screenshots convert more impressions to downloads. Compelling descriptions seal the deal.

ASO Quick Wins

If you are starting from zero, prioritise these high-impact activities:

Optimise your title with primary keywords
Rewrite first three lines of description with benefits
Redesign first two screenshots with benefit-focused captions
Implement native rating prompts at positive moments
Research and target 5-10 achievable keywords

These five actions often deliver 50%+ improvement in organic performance.

Conclusion

ASO is not optional for mobile apps. With millions of apps competing for attention, visibility determines success more than quality alone.

Start with fundamentals: relevant keywords, compelling screenshots, healthy ratings. Measure results, iterate continuously, and monitor the competitive landscape.

The best time to start ASO was before launch. The second best time is now.

Your app deserves to be discovered. Make sure the stores—and users—can find it.