The specific method of viewing multiple security cameras at once depends on the software or devices used to manage them. In general, there are multiple ways: VMS, NVR, multi-channel DVR, mobile app and/or web browser. A mobile app is the cheapest and easiest method for viewing multiple security cameras at once. All you need is the universal ZoomOn home security app, where you can connect any cameras and other devices. With ZoomOn security cameras can be accessed through a web browser.