Good wireless indoor home security camera provide solid motion and sound sensitivity, alert types (motion, sound) and frequency, placement flexibility, image quality (1080p video, wide angle lens, night mode, digital zoom), and speaker and microphone sound quality. They have multiple smartphone apps and storage options (for example, expandable microSD slots, online storage, etc).
Some of the new cameras also provide Geofencing, which automatically sets the camera to away mode and starts detecting for motion when you leave a predetermined area,
Before you decide to purchase an indoor wi-fi camera, decide where in your house your will put the camera, how you will use them, and who will have access to the footage.
Also remember that an indoor wi-fi camera is no substitute for proper home security. At best it can alert you and provide documentary proof.
The best indoor Wi-Fi camera for daily use: Logitech Logi Circle (built-in rechargeable battery)
The second best indoor Wi-Fi camera for daily use: Netgear Arlo Q (highly customizable alerts, activity zones, and free seven-day video storage)
The best affordable indoor Wi-Fi camera for daily use: Blink Home Security Camera (cheap, runs really long on batteries)
The best indoor Wi-Fi camera for smart-home enthusiasts: Nest Cam (advanced options require a subscription to Nest Aware)