App Localization Services for iOS, Android, and Cross-Platform Applications

App Store and Google Play ASO Localization — Keyword Research for Each Market

App Store Optimization (ASO) localization is the component of app localization that most directly drives new user acquisition — and it requires market research, not just translation.

Why translating your English keywords doesn't work: The keywords that drive app discovery in the US App Store differ from those in the German, Japanese, Korean, or Spanish App Store — not just in language but in the specific terms users actually type when searching. A US user might search "calorie counter" while a German user in the same category types "Kalorienrechner" — the direct translation — but a Japanese user types "カロリー管理" (calorie management). If your iOS keyword field contains the literal translation of "calorie counter" in Japanese, you may be optimizing for a term nobody searches.

iOS App Store keyword constraints: iOS has a dedicated 100-character keyword field (comma-separated, spaces don't count between keywords). These 100 characters are some of the most valuable real estate in your App Store presence — they directly affect your app's visibility in App Store search. TheWordPoint researches the highest-volume relevant terms for your category in each target App Store market and populates the keyword field accordingly.

Google Play ASO: Google Play has no dedicated keyword field — keywords must appear naturally in your app's title, short description, and full description. Google's algorithm reads these fields for relevance signals. TheWordPoint writes localized descriptions with target- market keywords woven naturally throughout.

App Store listing elements localized: iOS App Store Connect: App name (30 chars) · Subtitle (30 chars) · Description (4,000 chars) · Keywords (100 chars) · Promotional text (170 chars) · What's New text

Google Play Console: App name (50 chars) · Short description (80 chars) · Full description (4,000 chars) · What's new text

React Native, Flutter, and Xamarin App Localization

Cross-platform apps built with React Native, Flutter, or Xamarin reach both iOS and Android users from a single codebase — and each framework has its own i18n approach that TheWordPoint works with natively.

React Native localization: React Native apps most commonly use react-i18next or react-intl for internationalization. Strings are stored in JSON files (one per locale) — typically a structure like locales/en/translation.json, locales/de/translation.json. TheWordPoint receives your source JSON and returns translated JSON files in the same key-value structure for direct integration. Namespace separation (for large apps with separate translation files per feature module) is handled correctly.

Flutter localization: Flutter's official localization uses the flutter_intl package with ARB (Application Resource Bundle) files — a JSON-based format. The app_en.arb file is the source; app_de.arb, app_ja.arb etc. are generated translations. TheWordPoint translates ARB files for direct use with Flutter's gen-l10n tool, which generates the Dart localization code from the ARB files.

Xamarin.Forms localization: Xamarin uses RESX resource files (.resx) — the same .NET resource format as desktop applications. TheWordPoint delivers translated .resx files for each target locale.

Framework-specific considerations: All three frameworks require correct handling of interpolated variables (strings with dynamic values like {{username}} or {0}) — TheWordPoint preserves variable placeholders exactly as they appear in the source, in the correct position for the target language's natural word order.

Human Translation vs Machine Translation in Localization Services

You may easily come across business translation and app localization services that rely heavily on machine translation technology. While this might be reasonable for handling universally accepted terms and definitions, machine translation — even with advancements in artificial intelligence — still falls short of delivering the high standards and quality that come with human translation by native experts. For this reason, our service exclusively employs human translators for all client projects.

Relying solely on human expertise is absolutely critical given the complex nature of app localization. The process often involves intricate application design and development changes that cannot be machine-generated. These require expert programming and the proper architectural stacks for complete language adaptation and user experience optimization.

Another key factor in successful mobile app localization services is continuous communication between the translator and tech specialists. Native translators play a vital role in transforming all text, graphics, visuals, and multimedia elements into content that is not only accurate but also compelling, engaging, and culturally relevant for the target audience.

There’s simply no substitute for the nuanced touch of human translation in app localization, and our service fully understands this essential principle. Unfortunately, many other services fail to recognize its importance.

Push Notifications, In-App Messages, and Dynamic Content Localization

Mobile app localization extends beyond the app binary to every user-facing touchpoint.

Push notifications: Push notifications are often the highest-frequency branded communication with mobile users — and the first language-touchpoint with new international users after install. TheWordPoint localizes push notification titles and body text with awareness of display constraints: iOS shows approximately 65 characters for the title and 110 characters for the body on a lock screen before truncation. Notification content must be impactful within these constraints in each target language.

In-app messages: In-app messages via Braze, OneSignal, Intercom, Mixpanel, Leanplum, or custom implementations reach users during active sessions. TheWordPoint localizes in-app message templates for all major mobile engagement platforms — including modal messages, banners, slideups, and full-screen content cards.

Server-delivered dynamic strings: Many modern apps deliver content strings from a server (product names, promotional copy, onboarding content) that are not in the app binary. These strings require localization outside the native file format workflow — typically through JSON API responses or CMS export. TheWordPoint handles dynamic content localization via XLIFF or JSON alongside the binary string workflow.

In-app purchase descriptions: App Store in-app purchase products (subscriptions, one-time purchases, consumables) have their own localizable text fields in App Store Connect: display name, description, and promotional offer names. These are localized separately from the app binary and the store listing.

Email notifications triggered by app events: Transactional emails triggered by app activity (welcome email, receipt, notification digest) require localization consistent with the app's UI terminology and tone.

App Category-Specific Localization and RTL Markets

Category-specific localization expertise:

Fintech and banking apps. Payment method UI adapted for market-specific payment infrastructure (SEPA Direct Debit for EU, UPI for India, Pix for Brazil, Alipay/WeChat Pay for China). Financial regulatory disclosure language per applicable regulations. Currency formatting per CLDR locale standards. Credit/debit card form labels adapted for market conventions.

Health and fitness apps. Medical and clinical terminology. Health data privacy language (HIPAA-aware for US, GDPR-compliant for EU). Culturally appropriate health content — dietary, exercise, and wellness references adapted for cultural norms in the target market. Age-appropriate content labeling where applicable.

E-commerce and retail apps. Product catalog interface. Checkout and payment flow. Shipping and returns copy. Market-specific consumer protection disclosure language (EU consumer rights, UK Consumer Rights Act). Tax display conventions by jurisdiction.

Education and EdTech apps. Age-appropriate vocabulary control. Curriculum terminology specific to the target country's educational system. Learning content adapted for cultural relevance. → E-Learning Content Translation

Gaming apps. Gameplay UI, in-app purchase store, achievement text, and challenge descriptions. Cultural adaptation of game scenarios, character names, and narrative elements. → Game Localization

RTL app localization (Arabic, Hebrew, Farsi): iOS automatically mirrors the UI layout for RTL languages when semantic content attributes and auto-layout are correctly implemented. Android's android:supportsRtl and layoutDirection attributes handle mirroring when configured correctly. In both cases, mixed-direction text (RTL language with embedded numbers or English product names) requires Unicode bidi control characters for correct rendering. TheWordPoint provides native RTL speaker UI review confirming correct layout direction and text rendering — not just string translation.

How App Localization Works at TheWordPoint

• Audit localizable content. UI strings, store listing, push notifications, in-app messages, in-app purchase content, accessibility labels, and any server-delivered dynamic content.
• Export in platform format. iOS: Xcode Export Localizations (XLIFF). Android: strings.xml. React Native: JSON. Flutter: ARB files. Submit at thewordpoint.com/business-free-quote.
• App glossary and character brief. Feature names, app name, brand terms mapped to approved target-language equivalents. Character limits briefed for constrained UI strings.
• Human localization with length and plural review. Native-speaker app specialist translates strings with character limit awareness. Plural forms for all CLDR categories per language.
• ASO keyword research and listing localization. Store listing localized with target-market keyword research. iOS keyword field populated with market-researched terms.
• Delivery in platform format. iOS: translated XLIFF for Xcode Import Localizations. Android: strings.xml in res/values-{locale}/ structure. React Native/ Flutter: JSON/ARB in source format. Store listing as formatted text for direct upload.

Reviewed and updated  on September 3, 2026 by

Christakis Christodoulou