I'm going to be honest. I don't usually pay for iPhone apps. I'll cut it off right as the trial period is about to expire. There's no iPhone app I've really needed bad enough. Except for the Cloud Baby Monitor app. It's the best $5 I have spent. $4.99 to be exact.
No, I don't have kids, but I do have a dog and I have used this multiple times when we travel with him. I didn't like when we headed out to explore or would go to dinner and I couldn't check on him. We have Blink cameras at home, but it would have been a process to try and take those with us. So, I did a little research and found the Cloud Baby Monitor.
As long as we have had wifi where we are, it's worked seamlessly. You'll need two different devices. I always travel with my iPad, so that is the "baby unit." I set it up facing the area I know he'll be in most often.
Then, when I want to check on him, I just open the app on my iPhone, tap the "parent unit" and there he is! It's been great quality video and sound for me. You can even set up a lullaby to play for a specific period of time, but I found it to drain the iPad battery a little too quickly, so I don't use it.
I love being able to see my dog now when we're out. It gives this crazy dog mom peace of mind.