I installed this app last night and it worked pretty well. I like how you only hear any "noise" whenever your child (or any other sound that the android device picks up) makes a sound. So, unlike our other older model baby monitor, which has the constant white noise emitting from it all night, this app only lets us hear when an actual sound occurs. No constant white noise.
I'm using an old Original Motorola Droid as the Child device (Which was actually in the back of a drawer) and the only problem I had so far was that the device dropped the Wi-fi signal at around 4:30 in the morning. I'll chalk that up to a device issue, not an application issue, since I have that old thing running a custom ROM of Android 4.1...I think that device stopped receiving updates after Android 2.1 or something. When the device lost wifi signal, it prompted the Parent device, my wife's phone, to start playing an alarm clock type of notification that woke us up. In theory, this is actually a really great idea, since the app only lets you hear when noises are being made, not a constant white noise. So, it's not like the app will just stop working and you won't know about it...so you can sleep calmly and know that the app is actually monitoring your baby as it should be. But, being awakened by an unexpected alarm clock before you're true daily alarm clock time is kind of annoying, but as I mentioned, it is a necessary feature since the app requires a constant data connection of some sort. That probably won't happen on newer devices that have better radios and better signal reception.
The app starts off with like a trial period of four hours of free listening and you can earn credits and stuff by sharing the app or posting on facebook and stuff. The paid version is regularly like 6 bucks or something, but if you use the promo code ANDROIDPOLICE you can get unlimited listening time for %80 off for like a $1.50 or something. I think that code is only good until the end of February. So for $1.50, I'd give this app a solid 5 star rating. Hopefully the developer stays good on updates and bug fixes, but like I said, for $1.50...I'd have to dig deep to find anything more to not consider this a good buy. Hope this helps!