Dophigo video doorbell

It's a bit rudimentary and tacky but it works. It's powered by a 18650 battery (easily available as all the vapers use them) which it's claimed will last for 3-4 months on a charge. It's 2.4 GHz only. Picture quality is quite good. Alerts are quite fast (faster than Ring). It doesn't have a PIR and activates only when the bell is pressed. Only 10 seconds of video are recorded. Recorded videos are stored in the Cloud. No subscription. Chimes, apart from the default ding-dong, are hideous. When I first tested it a bell press would give the ding-dong followed by the spoken message "Please wait." Unfortunately it updated it's firmware and the spoken message is gone. Instead the ding-dong repeats several times. Not nice. Audio quality is not great.
All in all it is a bargain at €25.

Forgot to mention that the indoor chime also flashes blue when there's a ring at the door -- handy for a deaf person.
And, although there's no live stream function using the app, if you set up the Amazon Alexa skill you do get live streaming with an Echo Show.

I checked again and found it in "Trial functions" in the app. It does work but there is a warning that battery consumption will increase. There are two modes available -- Sleep mode and Wake mode. Sleep mode is the default -- the doorbell comes to life when the button is pressed. If Wake mode means that the camera is permanently live I'd imagine that battery consumption will increase drastically.
Wake mode must be enabled for use with an Amazon Echo Show.