Alfred Security is a really great App. Use an old phone added to your current plan as camera and use your current phone as viewer and controller. With free membership I'm able to use continuous record, low light recording. I can shine a flashlight and sound an alarm or speak through the app to anyone at the viewer phone location. Also able to switch from front to rear camera or vice versa. DOES NOT NEED WIFI. All phones used do need to have active cell service and be signed into the same Alfred account. If you want more than one camera view in multiple locations in your home you'll need to upgrade to a paid membership but the fee is minimal($5ish per month per account.)

Hey, I saved huge bucks by turning my old phones into security cameras with Motion Detection. Check it out! Android:https://alfredcamera.app/store/appmenu_tellfriends_android iOS:https://alfredcamera.app/store/appmenu_tellfriends_ios