Hi Makeda,
First issue.
When you are inside your home your smartphone connects to the LAN via wifi. When you leave the house your smartphone connects to your Internet Service Provider, your provider. Then you cannot use the IP to your computer which is something like 192.168.x.x:8100. That can only be used when you are connected in your house. To connect to NCS from outside you need to follow this Accessing Netcam Studio remotely using Web Client or Smartphone App IT is the same procedure if you use Webcam or Netcam Studio.
Second issue.
If you are running motion detection it will of cause start recording when you are in the house. When you leave and nothing triggers motion detection there will be no recordings. I am not certain how you have configured this, though.
-Henrik