Recommended WiFi camera?

[ROBOCRIPPLE]

I'm looking for a WiFi security camera that I can place just by the back door of my house, on a ceiling or a wall. The picture quality doesn't need to be great, just decent (like 720p). I'd like the WiFi connection to be good; I have the modem/router combo in my room where my computer is, but we do have an extender in the living room, which is closer to the back door but on the opposite side of the house, which is not big, BTW. I'd also like to have alerts/notifications on my phone; very handy whenever my cat wants to come in after I let her out and I can't hear her meowing.