Simple and cost effective CCTV Question

Evening all,
Am after some advice on CCTV systems and thought I'd ask on here before losing hours researching the myriad on online resources for my query...
So,
I need a simple to set up and work, relatively cheap system of 3x cameras where a smartphone can be used to monitor 3x rooms of a dwelling at the same time. The kit needn't be discrete or disguised or even ruggedised come to think of it. Am torn between wired/Wi-Fi and powered by electricity/battery. I need it to be able to be watched real time so storage is not important and I'd rather not pay for subscriptions.
Any top tips of pointers would be much appreciated.
Andy

I bought one of these for the garage as recommended by Big Lad on here.
Ridiculously good for even 3x what it costs. Its under £30 !!

The quality is amazing, even in pitch black. Daytime even better,motion activated with adjustable sensitivity.. You can listen in and even speak through a mike, frightens the daylights our of folks!!
It works off of a really simple and effective app, viewing from anywhere over the net and you can link several together. It records to an SD card, or you can subscribe to their cloud ( which is how they make their bucks I suspect)

Yi Wi-fi 1080p camera

Blimey, that looks ace Oldrat, great value for money. Will add it to the list ��
Many thanks. Andy

I have the older model to this

Security Camera with Auto Tracking Mibao IP Camera Wireless 1080P WiFi Camera with Remote Surveillance,Motion Detection,Video Recording,APP Alarm,IR Night Vision,Two-Way Audio https://www.amazon.co.uk/dp/B07KWQR1WF/ref=cm_sw_r_cp_apa_i_vYLvDb1F97MRR

Infra red, tracks, records and emails. I think there are a load of these in diferent cases but the same kit inside.

Any recommendations for an outdoor one please?