As the update arrived people updated their devices to the latest android version and they were forced to use Google's own Hangout app the default SMS app.
So if you to to have a separate application for sending messages or mms then you can Download KitKat SMS- Android 4.4 SMS
CLICK HERE TO DOWNLOAD
• Kitkat SMS is FREE
• Support SMS MMS on Android 4.4
• Support Android Latest Kitkat - Android 4.4
Note:To use Kitkat SMS separately from google hangout application please set this Kitkat SMS as your default SMS app.