amazons Blink setup is decent
the bell is 40 quid, you can see who is at your door
if you want to record all of it, you needs the synch module, which is £35 quid, but you can add upto 10 devices to that module ( so a few camera's etc etc ) and the module will record to a USB stick
you can also save it to the " cloud " for 2.50 a device, or 8 quid unlimited ( per month )
bell battery lasts for 2 years they say, on 2 AA batteries
if you are going with the Blink, the inside min camera are 25 quid ( people stick them In the window pointing out etc ) or the outside cam are 60 quid
very easy to setup
I do have slight issues with the non-cloud option though, someone could break in, be seen by the camera's then steal the Synch module ? ? ? but they wouldn't know its cloud based either, so I guess its a visual deterrent