The battery-powered Blink Indoor requires a Sync Module to operate, and if you don't have one from a past Blink camera purchase, you can buy a next-gen Sync Module 2 bundled with a Blink Indoor camera for $80 (although Blink tells me this camera will work with existing modules).
The Ezviz Mini 360 Plus security camera costs $70 and has a 340-degree panning angle and an 80-degree tilting angle.
You can adjust the camera's angle manually in the app or opt in to its "auto-tracking" mode that follows motion activity around a room. Unfortunately, it didn't do a good job of tracking my movements unless I walked very slowly.
Google's Nest Cam IQ has an 8-megapixel, 4K image sensor and improved 12x digital zoom for access to a 24/7 live video stream. A hardware upgrade improves the audio quality of Nest's two-way talk function.
Samsung's SmartCam HD Pro is a direct Nest Cam Indoor competitor, but it didn't quite match the crispness of Nest Cam's videos on either the Web or its mobile app. Its components also felt cheap in comparison. It does have a ton of useful features, though, including local SD card storage.
The Wyze Cam, Wyze's cheapest home security camera, costs just 20 bucks. It has 1080p HD resolution, 110-degree field of view, motion, sound and person alerts. It also has advanced sound alerts for smoke and carbon monoxide detection -- and 14-day free cloud storage.
There's also a microSD card slot, but the card is sold separately.