EGK Microelectronic Solutions Group logoEGK ASO LabFree App Store Optimisation Toolkit
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Rank higher. Get more installs.

Free App Store Optimisation (ASO) tools and a practical playbook for the iOS App Store and Google Play — built by EGK, an engineering team that ships apps for a living.

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Free tools

ASO metadata & keyword tools

Everything runs locally in your browser. Nothing you type is sent or stored.

1 · Metadata character counter

2 · iOS keyword field optimiser

Uses the iOS fields above. Removes spaces, duplicates and words already in your name or subtitle (Apple already indexes those), then shows the characters you can still use.

Fill the iOS fields, then press the button.

3 · Keyword density checker

Top words appear here. Aim for natural use of your main keywords 3–5 times; avoid stuffing.
Tool 4

30-point ASO checklist

Tick what you have done. Your score updates live.

0 / 30
Guide

How App Store Optimisation works

ASO has two jobs: be found (visibility) and convince (conversion). Work on both.

Visibility

Name, subtitle, keywords, description (Play), category, localisation and install velocity decide where you appear in search and browse.

Conversion

Icon, first three screenshots, preview video, rating and reviews decide whether a viewer taps Install.

Retention signals

Crashes, uninstalls and engagement feed back into ranking. A fast, stable app is an ASO asset.

Metadata limits at a glance

Character limits by store field
FieldiOS App StoreGoogle PlayIndexed?
Name / Title3030Both
Subtitle / Short desc.3080Both
Keyword field100NoneiOS only
Promotional text170—No
Description4,0004,000Play only

Playbook

1Research keywords by intent
Start with 30–50 candidate phrases. Prefer relevant, mid-competition terms over generic head terms. Check autocomplete suggestions in both stores and study 5 direct competitors.
2Write the name and subtitle for humans first
Put your brand plus the single strongest keyword in the name. Use the subtitle for a second keyword and a clear benefit. Never repeat a word across fields on iOS.
3Fill the iOS keyword field completely
Use all 100 characters, comma-separated with no spaces. Skip plurals, your own name and category words Apple already indexes.
4Write a Play description that reads naturally
Google indexes the full text. Open with the main benefit, use the primary keyword in the first 2–3 lines and repeat it naturally, with bullet features and a clear call to action.
5Design for the first three screenshots
Most viewers never scroll. Lead with the core outcome, use big readable captions, and localise the captions per market.
6Localise
On iOS each localisation adds its own indexed keywords. Translate and research keywords per language rather than machine-translating.
7Earn ratings, answer reviews, iterate
Prompt for a rating after a success moment, reply to reviews, and A/B test icon and screenshots with Product Page Optimization (iOS) or Store Listing Experiments (Play).
FAQ

Frequently asked questions

?What is App Store Optimisation (ASO)?
ASO improves an app's visibility in store search and its conversion from page view to install, using metadata, keywords, creatives, ratings and localisation.
?What are the iOS metadata limits?
App name 30, subtitle 30, keyword field 100, promotional text 170, description 4,000 characters.
?What are the Google Play metadata limits?
Title 30, short description 80, full description 4,000 characters.
?Is the keyword field indexed on Google Play?
Google Play has no keyword field. It indexes the title, short description and full description, so keywords must appear naturally in those.
?Are these tools really free?
Yes. Everything runs in your browser, nothing is uploaded or stored, and no account is needed.