Crowdl.io is described as 'free translations manager with crowd translations features. Create a project, load your strings, and share your project's link with your translators' and is an app in the Development category. There are more than 10 alternatives to Crowdl.io for a variety of platforms, including Online / Web-based, SaaS, Mac, Windows and Linux. The best alternative is Linguee, which is free. Other great apps like Crowdl.io are Crowdin (Paid), POEditor (Freemium), Poedit (Freemium) and Texterify (Freemium).
POEditor is a localization management platform, suitable for collaborative and crowdsourced translation projects. It makes managing website localization, app localization, games localization or other software localization an easy process.
Poedit is cross-platform gettext catalogs (.po files) editor. It is built with wxWidgets toolkit and can run on any platform supported by it (although it was only tested on Unix with GTK+ and Windows).
OneSky (oneskyapp.com) is a simple & affordable translation service specialized in mobile apps (iOS, Android), e-commerce and websites, supporting 50+ languages. It offers the most powerful localization project management platform for team collaboration.
Localize is a very convenient service that provides SDK and online update for iOS and Android apps translation. You can manage your localisation files without the need to think about which version of the app you're updating.