Send predefined sms/text message to group with a shortcut
Check out WithU app 

WithU connects you with your family and friends in any problem. WithU is an emergency App that, at the click of the Start button begins sending out alert messages in every 2 minutes to your contacts that you saved into the app as the receivers or guardians.
Enter Contacts Numbers of People whom you wanna inform whenever you are in Trouble. If you feel Unsafe, Distress, just press Green Start Button, It will send SMS (With your location and Time) to the Saved Numbers.
The message says "I am in Problem. Please help me. My Location is (Your Current Location)". Even if you have not Internet Connectivity , it send SMS to your contacts with message "I am in Problem. Please help me".

You can place the button on your homescreen.