I think OP was asking about the possibility of making profit from making an app and monetizing it, guys. In that case, yes, of course. As long as people use it, you will get ad revenue.
There are a number of apps that can make you a small amount of money. Basically, it's like some extra money on the side, not enough to live on. I use the swag apps and can make about 80 cents a day with those, and that's basically with about 2-3 minutes of set up time, so essentially "passive earning." You can also do mpoints games in your spare time to earn gift cards. I enjoy the games and do them whenever I am waiting for something or just chilling since they can be pretty fun. Perk TV isn't what it used to be from what I've heard, and I have not had any good experience with it. Basically, between all the things I do with my smartphone, I earn about $14 a week. That's not a lot, but it's definitely helpful.
There are a few applications that pay quite nicely for scanning products, or for taking pictures of certain products at certain stores whilst you are out and about. I don't really go out all that much, so these applications would not be the best thing to make money with. Add to that the fact that they only seem to be available for IOS or Androids, and I don't have either smartphones with those operating systems.
Well, others have made money from apps they created. The trick I believe is to come up with an app that will either solve a problems for many people or that will entertain them fully. Also with so many apps coming out daily you will surely have to market your app properly. You may also need to keep the cost down.
I agree in the sense that money making applications shouldn't just be about making money, because most of the time, and as I have said numerous times above, to make the money you have to spend money in electricity, and you are usually spending more than you are earning back. But if the application gives you something in way of entertainment, whilst you make the money then it doesn't seem so bad.
I mean I'm sure if a lot of people downloaded it then you would be able to make money from it. I'm not sure how much money you would be able to make though. I doubt that it would be enough to make a living from. There isn't an easy way to just making something and then thinking that you will be able to make money from that. Apple doesn't give a ton of money to you for making the apps because they have to take their own share of it. I think it's dumb they do that, but they do. Because I'm sure that they take way more than they should. If this is something that you want to do then I would suggest that you try it out and just see how much you are able to make from it.
I currently have my finger in many different pies, as far as money making opportunities online go, and I still am not earning enough money - or a reliable enough source to be able to move out of my parents' house and live on my own. Smartphone application that you can make money from pay absolute peanuts.