Secure Mobile Apps

To achieve our goal of a comprehensive, privacy- and security-focused communications solution, Guardian is driven both by internal development and the open-source community at large. In cases where a viable, vetted, and usable product already fills the communications needs of our target audience, we will recommend apps that work.

Our Apps

Our apps are available on Google Play, Amazon, our F-Droid Repository, or download the APK directly from us.
Expert users can also download and test our nightly builds

Orbot: Proxy With Tor
Orbot brings the capabilities of Tor to Android. Tor uses Onion Routing to provide access to network services that may be blocked, censored or monitored, while also protecting the identity of the user requesting those resources.
Google Play | F-DroidDirect Download (.apk)| View source code

ap_resizeOrfox: Browser for Orbot
Orfox is built from the same source code as Tor Browser (which is built upon Firefox), but with a few minor modifications to the privacy enhancing features to make them compatible with Firefox for Android and the Android operating system.
Google Play | F-Droid | Learn More

ChatSecure: Private and Secure Messaging
ChatSecure (formerly “Gibberbot”) is a full featured mobile messaging application integrated with the “Off the Record” encrypted chat protocol, that allows you to chat with anyone, anywhere using the XMPP chat standard.
Google Play | Direct Download (.apk) | View source code

ObscuraCam: The Privacy Camera
A secure camera app that can obscure, encrypt or destroy pixels within an image. This project is in partnership with, a human rights video advocacy and training organization.
Google Play | Direct Download (.apk) | View source code.

Pixelknot: Hidden Messages
Have a secret that you want to share? Why not hide it in a picture? With PixelKnot, only your friends with the secret password can unlock your special message. Everyone else just sees a pretty picture. It’s a fun and easy way to share hidden messages without anyone knowing. Take those pixels, twist them in a knot, and see for yourself!
Google Play | Amazon Appstore | Direct Download (.apk) | View source code.

Ostel: Encrypted Phone Calls
A tool for having end-to-end encrypted phone calls. This is a public testbed of the Open Secure Telephony Network (OSTN) project, with the goal of promoting the use of free, open protocols, standards and software, to power end-to-end secure voice communications on mobile devices, as well as with desktop computers.
Download app [Android, iPhone, Blackberry, Nokia, PC, Mac, Linux]. View source code..

Desktop Applications

KeySync: Syncing Trusted Identities
Sync your trusted OTR and OpenPGP identities between desktop and mobile, and multiple apps.
Direct Download Page | View source code.

3rd party applications we support and recommend

K-9 and OpenKeychain: Encrypted E-mail
K-9 Mail is an open-source app based on Android’s built-in Email app. The project is focused on making it easy to manage multiple accounts and large volumes of email, as well supporting OpenPGP encryption using OpenKeychain.

K-9: Google Play | View source code.
OpenKeychain: Google Play | View source code.

CSipSimple: Encrypted Voice Over IP (VOIP)
CSipSimple is a free and open source SIP client for Android that provides end-to-end encryption using ZRTP. This app is compatible with an Ostel account for making secure phone calls on Android.
Google Play | Direct Download (.apk) | View source code.

Linphone: Encrypted Video and Voice Over IP (VOIP)
Linphone is a free and open source SIP client for Apple iOS, Android, and desktop that provides end-to-end encryption using ZRTP. This app is compatible with an Ostel account for making secure voice and video calls.
Google Play | iTunes | View source code.

Signal (was TextSecure & Redphone): Privacy Messenger
Signal, developed by Whisper Systems, provides a robust encrypted text messaging solution, but it is only compatible with other Signal users.
Google Play | View source code.

Osmand: Offline Maps and Navigation
Osmand is the most private map app because it works completely offline. The map data is downloaded from OpenStreetMap. As of version 2.0, it can also understand many different location sharing URLs, as well as download map data via Tor by setting the proxy.
Google Play | View source code.


Here are some resources, videos and how-to walkthroughs of our apps.

How to: Browse Freely



How to: Chat Securely



How to: Call Securely