This app was mentioned in 2 comments, with an average of 1.00 upvote
Wow, thanks. Hardware looks decent enough.
It shows it goes through the cloud though for "real time" intercom. Also seems very inexpensive, makes me a bit cautious. The software app on Google Play doesn't have the best reviews either. Although I don't know if most of those issues are with wi-fi or PoE. https://play.google.com/store/apps/details?id=com.yoosee&showAllReviews=true
I like the idea, it should be just this simple. A network jack in the back to an NVR, just need a way to chime and video chat real-time without cloud.
I often download from http://choilieng.com, this site generate apk from Play store url. copy app url from Play store (like https://play.google.com/store/apps/details?id=com.yoosee)
Paste this url to search box on this site: http://choilieng.com (Android is open-source and Google allow anyone to get apk file directly from their host). Enter an get result
If lucky, you will get apk file of your wanted app/app with all versions (oldest to latest at the bottom right corner of the site). Just download the version you wish, and install on your phone.
I do some check and I know this is pure apk with original signature from developers, so this is a trusted site.