Low-cost home monitoring system on Android with camera and doorbell

Hello,
due to the fact that I am leaving my house in the countryside, I would like to monitor it somehow,
i would need a simple, inexpensive and relatively Polish system, also working on android.
what would I need?
Operation of one camera, in front of the entrance,
operation of a bell, so I would know when someone is calling, so I would be able to see
support for at least one thermometer.

or maybe the Satel control panel alone would be enough? And I would fit a reed switch in the gate and gate?

Fibaro (I know, but you don't need such a machine for an unused house. ),
Nexwell, PLC ( not my fave:) )

i mean something, very non-invasive, and not too expensive
Please make any suggestions

Perhaps it would work on Satel, but let the Satel guys have their say.
As for the control, how about something like this? http://www.psenso.com/pl/gsmcontrol/models
As for vision, probably some IP camera, but which one it is, I can't say....

Get interested in a lan controller or a gsm controller - it depends how you want to communicate. You will buy a relay module and you can control whatever you want. In addition, you will examine temperature, power status and create a 'presence simulator'.