Have three cams but am only able to record on one at a time. Can I record on all?
You can record the live feed on your phone only one camera at a time (because you can only view one live stream at a time).
However, you can install a microSD card into each camera and record either continuously or motion events within the camera for later playback. A 32GB Class 10 mSD card is recommended and you can find those for about $10-12 on Amazon or other online or brick and mortar stores.
One other option if you have an Android device is to install the TinyCam app which can view multiple cameras at a time. I believe (possibly with an in-app purchase) you can record multiple cameras with this app. Unfortunately, there is no iOS version.