libwajava is a WhatsAPP library for Android. Thanks goes out to the WhatsAPI team @ https://github.com/venomous0x/WhatsAPI for doing all the reverse engineering.
final WAClient client = new WAClient("YOUR_NUMBER_WITHOUT_PLUS", "PASSWORD_IN_BASE64", "DISPLAY NAME");
client.connect(new WAConnectCallback()
{
@Override
public void onConnect()
{
try
{
System.out.println("Connected :-)");
client.sendMessage("SOME_NUMBER", "Hey there from libwajava!");
}
catch (Exception e)
{
e.printStackTrace();
}
}
@Override
public void onConnectFailure(Reason reason)
{
System.out.println("Couldn't conenct :-(");
}
});