App UFO is an AI-powered app localisation tool for macOS that translates .xcstrings files into 36+ languages while preserving plural rules, so developers can ship their apps in multiple markets with confidence. Designed by developer Melvin Zammit, App UFO runs natively on macOS and integrates directly with Xcode workflows.
What is App UFO?
App UFO is a desktop application for macOS that takes Apple's .xcstrings localisation files as input and outputs fully translated versions in up to 36 languages. It uses AI to generate context-aware translations that respect your UI's character limits and keep brand names untranslated. Created by indie developer Melvin Zammit (app developer since 2012), the app is sold through the Mac App Store.
Key Features
- AI-powered translation — No API keys required for the monthly/yearly plans; AI translations are included with phrase quotas (25,000 per month, 250,000 per year).
- 36+ languages — Translate your app strings into a wide range of languages, with automatic preservation of plural rules so your UI doesn't break.
- Drag-and-drop workflow — Simply drop your .xcstrings file into App UFO and get translated files ready to export back to Xcode.
- Character limit enforcement — Set maximum character counts per phrase to ensure translations fit your UI layout.
- Brand name protection — Mark specific words as untranslatable so your brand name appears identically in every language.
- Reverse translate — Use Apple Translate to check translations from languages you don't read (e.g., Chinese or Arabic) to verify accuracy.
- Unlimited apps and languages — No per-app or per-language restrictions; translate as many apps as you need.
Who is it for?
- iOS and macOS app developers who need to localise their .xcstrings files for multiple markets without manual translation effort.
- Indie developers who want to expand their app's reach beyond saturated markets like the US App Store.
- Small app teams that lack dedicated localisation resources and need a fast, affordable AI-based solution.
What can you do with App UFO?
- Localise a finished app quickly: Drag your .xcstrings file, choose target languages, and get translated files ready to drop back into Xcode — all in a few minutes.
- Expand into non-English markets: Translate your app into languages like Chinese, Arabic, Spanish, or French while maintaining UI integrity and brand consistency.
- Verify unfamiliar languages: Use the reverse translate feature to confirm translations from languages you don't speak, reducing the risk of publishing incorrect content.
How does App UFO work?
After downloading from the Mac App Store, you open App UFO and drag your .xcstrings file into the app. Select the languages you want to translate into, optionally set character limits and protected words, then start the AI translation. The app outputs translated .xcstrings files that you can export directly back to Xcode.
Pricing
App UFO offers three tiers: Monthly at €9.99 (25,000 AI phrases per month), Yearly at €69.99 (250,000 AI phrases per year), and a Lifetime option at €39.99 (bring your own AI key, no phrase limit, more privacy). All tiers include unlimited apps and languages, glossary support, brand name protection, and reverse translate. Prices may vary by country.
