Send sms in android Application using Intent and SmsManager API

Using SmsManager API

                    SmsManager smsManager = SmsManager.getDefault();
                    smsManager.sendTextMessage("phoneNo", null, "sms message", null, null);

Built-in SMS application
                 
                    Intent sendIntent = new Intent(Intent.ACTION_VIEW);
                    sendIntent.putExtra("sms_body", "default content");
                    sendIntent.setType("vnd.android-dir/mms-sms");
                    startActivity(sendIntent);

Require Following Permission for Both

          <uses-permission android:name="android.permission.SEND_SMS" />