Not familiar with MPRMS, but have used
IP Cam Viewer (by Robert Chou) (there's a basic, lite, and pro ($3.99) version--not sure how basic differs from lite, though) for years.
The big issue with connectivity is, of course, the quality of the cameras' network connectivity and having the proper network setup made (i.e., knowing your external IP address, having the port associated with your camera properly forwarded in your router, and doing the proper setup in you device and that the forwarded port matches what you have configured in the camera).
I would first verify that you can get local connectivity to your camera from your house using your local network address first (i.e., your router's local / internal address for your camera (something like 192.168.1.*), and double check the port that you are using for the camera being tested.
After you've verified that, use whatismyip.com or similar site to verify your computer's external network address, and then try using that (i.e., http://<external-IP-address>:<port #>).
Best of luck--if all else fails, check your camera's website for examples and other documentation.
