StealthChat!

With Viber, everyone in the world can connect. Freely. More than 460 million Viber users text, make HD-quality phone and video calls, and send photo and video messages worldwide over WiFi or 3G - for free. Viber Out can be used to make calls to non-Viber landlines and mobile numbers at low rates. Viber is available for many smartphones and platforms.

ChatSecure is a free and open source messaging app that features OTR encryption over XMPP. You can connect to your existing accounts on Facebook or Google, create new accounts on public XMPP servers(including via Tor), or even connect to your own server for extra security.

Threema is a new mobile messaging app that puts security first. With true end-to-end encryption, you can rest assured that only you and the intended recipient can read your messages.

Conversations is a privacy focused, open source XMPP Texting [Jabber] client for Android 4.0+ smart phones with wife-approved easy encryption [OTR, OMEMO, or GPG].

Open source Jabber (XMPP) client with multi-account support, clean and simple interface. Being both free (as in freedom!) and ad-free, Xabber is designed to be the best Jabber client for Android .

Zulip is a group chat app.

Snapchat is the fastest way to share a moment with friends.

Wickr is a free end-to-end encrypted text, video, picture and voice messenger with full sender control.

BlackBerry Messenger is a FREE messaging app available for Blackberry, iOS, Android and Windows Phone. BBM has unique features to protect your privacy and keep you in control:• Retract – The ability to take back messages and photos, even after you’ve sent them. Retract before they’ve been ‘R’ (Read) and they’ll never know!• Timer – The ability to set a timer so that a message or photo can only be viewed for a set amount of time before it disappears.• Private Chat – A special chat mode that disappears without a trace when you’re finished.• The BBM PIN – A way to share your contact information, without sharing your phone number or email address. This keeps you in control of who can send you messages at all times. Once blocked, they have no way of contacting you. »

Private instant messaging via secure, distributed technology.

Dasher lets you do more than just text message. It's messaging with benefits:

Free secure Germany-based messenger available for iOS, Android and Windows Phone. Sicher has true end-to-end encryption of both text messages and file attachments. With anonymous push notifications and the ability to set a timer for when messages will self-destruct (a manual purge option is also available), Sicher also includes password protection for the app itself.