Subrosa is described as 'open source, end to end encrypted messaging app. It supports text, voice and video calls, and all communication is end to end encrypted' and is an app in the Social & Communications category. There are more than 25 alternatives to Subrosa for a variety of platforms, including Windows, Mac, Linux, Android and iPhone. The best alternative is Telegram, which is free. Other great apps like Subrosa are Jitsi (Free, Open Source), Jitsi Meet (Freemium, Open Source), Skype (Freemium) and Tox (Free, Open Source).
Jitsi (previously SIP Communicator) is an audio/video and chat communicator with full encryption that supports protocols such as SIP, XMPP/Jabber, ICQ/AIM, Windows Live, Yahoo!, GTalk/Hangouts extensions, as well as OTR, ZRTP, etc.
Go ahead, video chat with the whole team. In fact, invite everyone you know. Jitsi Meet is a fully encrypted, 100% open source video conferencing solution that you can use all day, every day, for free — with no account needed. What else can you do with Jitsi Meet?
Skype is the most popular free voice-over IP and instant messaging service globally. It allows users to text, video and voice call over the internet. Users can also call landlines and mobiles at competitive rates using Skype credit, premium accounts and subscriptions.
Wire is the most secure collaboration platform featuring messenger, voice, video, conference calls, file-sharing, and external collaboration –all protected by the most secure end-to-end-encryption. Why Wire?
WhatsApp is an iPhone and Android messaging app which allows you to exchange messages without having to pay for SMS. In addition to basic messaging WhatsApp users can create groups, send each other unlimited images, video and audio media messages.
Jami (formerly GNU Ring, SFLphone) positions itself as a potential free Skype replacement Open Source and cross-platform. Jami gives you a full control over your communications and an unmatched level of privacy.
Mumble was the first and is the most successful and wide spread free and open source software for VoIP. It was the first VoIP software to provide low-latency audio suitable for gaming, and at the same time was a pioneer in high audio quality at the same time.