Social Source Commons

The GNU Privacy Guard (GnuPG) enables people to securely exchange messages and to secure files with both privacy and strong authentication. GnuPG is a free software replacement for the PGP suite of cryptographic software.

Guardian Project port to Android: https://guardianproject.info/code/gnupg/

Based on the open-source Shadow browser from the University of Cambridge, Orweb works hand in hand with Orbot to provide web access that is able to circumvent web filters and firewalls, while also improving a users ability to remain anonymous online. Orweb also enables whitelist control of cookies, keeps no local history, disables Flash, and requires only Internet permissions, keeping you safe from malicious content. Beyond Tor, Orweb also supports any HTTP proxy server.

Ostel is a tool for having end-to-end encrypted phone calls. Our goal is to promote 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.

ChatSecure (Gibberbot) is a secure chat client capable of firewall and filter circumvention, surveillance blocking and end-to-end encryption. It works with Google, Facebook, any Jabber or XMPP server, such as OpenFire or eJabberD. Unlike Blackberry BBM’s broken single key security, Gibberbot uses the Off-the-Record encryption standard to enable true verifiable end-to-end encrypted communications.

Free unlimited, private, secure messaging with your friends over Facebook Chat, Google Talk, Hangouts, Jabber, Dukgo & more! Works with Android, iPhone, Mac, Linux or PC.

SMS server (broadcast hub) using internetless mobile technology to connect outside people like in: humanitarian aid, street protest, church, camp, building construction and so far.

Available at Google Play:
https://play.google.com/store/apps/details?id=appinventor.ai_maugiroe.Hubby

Open Data Kit (ODK) is a free and open-source set of tools which help organizations author, field, and manage mobile data collection solutions. ODK provides an out-of-the-box solution for users to:

1) Build a data collection form or survey (XLSForm is recommended for larger forms);
2) Collect the data on a mobile device and send it to a server; and
3) Aggregate the collected data on a server and extract it in useful formats.

Secure Android ROM

XDA-Developers Thread: http://forum.xda-developers.com/showthread.php?t=2317794

Guardian ROM is a custom android ROM for Galaxy Nexus and Nexus 4 devices. The ROM is completely Open Source and based off of the Android Open Source Project. The ROM aims to due the following:

Secure/Harden the android kernel with GRSecurity
Remove uneeded/Insecure binaries (Similar to SecDroid)
Replace insecure Text Messaging app with TextSecure
Include apps from the Guardian Project Installer (Optional add-on)
Include support for SQLCipher
Change Android Full Disk Encryption from AES-128 to AES-256 for more security
Allow for seperate Login and boot passwords
All of these have been completed except the final three which are underway but will take much more time.

Replicant is a free and open source operating system based on the Android mobile platform, which aims to replace all proprietary Android components with their free software counterparts. It is available for several smartphones and tablet computers.

CyanogenMod is an aftermarket firmware for a number of cell phones based on the open-source Android operating system. It offers features not found in the official Android based firmwares of vendors.

TWRP is a custom recovery built with ease of use and customization in mind. We started from the ground up by taking AOSP recovery and loading it with the standard recovery options, then added a lot of our own features. It’s a fully touch driven user interface – no more volume rocker or power buttons to mash. The GUI is also fully XML driven and completely theme-able. You can change just about every aspect of the look and feel.

Android is an open-source software stack for a wide range of mobile devices and a corresponding open-source project led by Google.

Firefox OS is a Linux-based open-source operating system for smartphones and tablet computers and is set to be used on smart TVs.

K-9 is an opensource email client based on the Email application shipped with the initial release of Android.
K-9 is focused on making it easy to chew through large volumes of email.
K-9 Mail is an open-source e-mail client with search, IMAP push email, multi-folder sync, flagging, filing, signatures, bcc-self, PGP, mail on SD & more!
K-9 supports IMAP, POP3 and Exchange 2003/2007 (with WebDAV).

This app will also remove all identifying data stored in photos including GPS location data and phone make & model. You can save the protected photo back to the Gallery, or share it directly to Facebook, Twitter or any other “Share” enabled app.

This is a free and open-source file encryption solution based on the original EncFS code. Cryptonite is fully compatible with all EncFS features. Cryptonite brings EncFS and TrueCrypt to Android. You can browse, export and open EncFS-encrypted directories and files on your Dropbox and on your phone. On rooted phones that support FUSE (e.g. CyanogenMod) you can also mount EncFS and TrueCrypt volumes.

REQUIRES ROOT ACCESS

AFWall+ (Android Firewall +) is an improved version of DroidWall front-end application for the powerful iptables Linux firewall.It allows you to restrict which applications are permitted to access your data networks (2G/3G and/or Wi-Fi and while in roaming).

Extension for Firefox for Android. Simple add-on for settings HTTP, SOCKS and SSL proxy settings. Works by default with Orbot: Tor on Android.

This is a simple open-source notepad app which demonstrates the capability of the SQLCipher for Android encrypted database library. All notes created and stored by this app are saved fully secured using industry standard 256-bit AES encryption. They are never stored in an unencrypted state on the disk, only in memory.

Features
Plays all files, in all formats, like the classic VLC.
Audio and video media library, with full search.
Support for network streams, including HLS.
Supports Android from version 2.1 (platform-7).
Supports ARMv6, ARMv7 and ARMv7+NEON.
Subtitles support, embedded and external, including ASS and DVD subtitles.
Multi audio or subtitles tracks selection.
Multi-core decoding, for Cortex-A7 A9 and A15 chips.
Experimental hardware decoding.
Gestures, headphones control.

Ghost Commander is a file manager for the Android™ platform with two panels. Its development was inspired by famous (Norton|Midnight|Total) Commander desktop applications, so if you are familiar with those great software, you will find the Ghost Commander familiar and a very convenient environment.

TextSecure encrypts your text messages over the air and on your phone. It's almost identical to the normal text messaging application, and is just as easy to use.

KeePassDroid is a port of the KeePass Password safe for the Android platform.

OpenDocument Reader, formerly known as OpenOffice Document Reader, allows you to read your ODF documents wherever you are. In the bus on your way to school? No problem! With OpenDocument Reader you can read and search through your documents in a very clean and simple way. Available for Android and Google Drive.

Scan barcodes on products then look up prices and reviews. You can also scan Data Matrix and QR Codes containing URLs, contact info, etc.

AdAway is an open source ad blocker for Android using the hosts file. It needs Android >= 2.1 and ROOT access.

Does not work for Android 4.3 updates
This application makes a backup or a protected backup of your device's root. This device must already be rooted: OTA RootKeeper doesn't have the ability to root devices. If several conditions are matched, OTA RootKeeper will make root survive OTAs, and anything else except /system partition formatting.

Sailfish brings and fosters innovation to offer unique differentiation and a competitive advantage for OEMs and ODMs, chipset providers, operators, application developers and retailers.