Poedit is a popular translation editor for XLIFF and PO files, with builtin support for Xcode XLIFF files, WordPress and gettext source extraction. It features quality checks, translation memories and collaboration functions (via Crowdin). It is a free app with a few paid conveniences such as online pre-translation and machine translation.
Other similar tools
Applanga is a flexible & easy to use cloud-based localization platform that automates the translation process for iOS, Android, OSX, […]
A Mac app and platform that offers continuous localization for your Xcode projects. LocalizeWiz completely automates the localization workflow by monitoring strings files in your Xcode projects for changes, so any new content is automatically localized to all your supported locales, and changes synced back to your Xcode project. You get to localize up to 300 strings or 3 projects for free, with additional paid plans to remove restrictions and translate your app to over 50 different languages. […]
A multi-platform localisation service. Localise lets you upload your source files in pretty much any recognised language file format, and collaborate with your team to translate your app into multiple languages. Once translated you can download your updated files, or use the iOS framework that provides over-the-air localisation so you can update your translations without having to submit your app for review. Localise has built in Google and Yandex machine translations, or you can buy translations for a price per word fee. […]
A localization SDK and platform for iOS and Android. The Qordoba SDKs work with the asset and localization files in your app to parse and ingest them into the Qordoba platform, a visual web-based solution for editing and managing mobile app UI and the metadata for your app. New languages or updated content can be delivered to your users via Qordoba’s SDK so you can add languages on the fly or remove and edit content in existing languages without needing to resubmit your application to the App Store. […]