Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...
Crowdin - Localize your product in a seamless way
TextMe - TextMe is a free calls and messaging application at both local and international levels.
POEditor - The translation and localization management platform that's easy to use *and* affordable!
Talkatone - Android App on. Google Play. Stop paying for cell minutes, texts & landlines; Turn your iPad or iPod touch into a phone; Call/Text even in areas with bad cell coverage; Call/Text when travelling without paying for expensive international minutes.
Lokalise - Localization tool for software developers. Web-based collaborative multi-platform editor, API/CLI, numerous plugins, iOS and Android SDK.