Update TODO.md

TODO.md

@@ -29,3 +29,30 @@ It was developed to be run on OSX.  The outputs are copied to the dist directory
 
 DMG is created with hdiutil
 EXE is created with makensis (brew install makensis)
+
+## Android APK
+
+System Requirements
+
+* Download [Android SDK](http://developer.android.com/sdk/index.html)
+* Download and install [Crosswalk](https://crosswalk-project.org/#documentation/getting_started) (Use Linux setup for OSX)
+
+Add to your ~/.bash_profile or ~/.bashrc
+
+```
+export CROSSWALK="<path to Crosswalk directory>"
+```
+
+To build the APK run the script:
+
+```
+sh android/build.sh [-d]
+```
+- The -d flag will package the apk in debug mode, allowing [remote debugging chrome](https://developer.chrome.com/devtools/docs/remote-debugging)
+- The APK file is in **android/Copay_VERSION_arm.apk**
+
+To install the APK in your device run:
+
+```
+adb install -r Copay_VERSION_arm.apk
+```