What kind of app is likely to make the most money if it's sold on the Android market? Games, utilities... what sells? What do people charge and how much of the asking price does the author actually receive?
(note: I haven't got an Android phone yet, so I'm clueless on how the Android market works... although I have got a copy of "Hello Android" by Ed Burnette, which I haven't read yet.)
Unfortunately, if you are only going into this to make money, you won't.
At this point in all mobile development there is huge competition and it always comes down to marketing and sales.
And most apps these days, especially in the Android market, are expected to be sold for free. The consumer, unfortunately, thinks it is their right to get all apps for free, so when you do charge for an app, you really have to market and push it to get people to spend their money on the app.
I was thinking if I write a game and get people hooked, I could sell extra levels, a bit like they did with Quake when that first came out. According to Wikipedia, Angry Birds is making $1 million a month from advertising on the Android version alone... that's obviously an extreme case, but the value of the market for Android apps will certainly grow massively over the next couple of years, and someone's got to be making money from it - it's a question of who will step up and be one of the someones.
Maybe I should rephrase the question, to "what are the major growth areas and opportunities that are likely to arise on the Android platform over the next couple of years (whether or not you're a greedy capitalist pig or a beardy borsch-supping communist)"?
For sure, if you can come up with a catchy game then that will do well for you - although the market is hotting up more and more in that section, so another alternative would be to find a niche that you know about and try and fill that.
If you want to go down the games path then there are loads of great libraries out there that you can try out:
Again my point is, it has little to do with your actual app to make money in these apps. I have 6 iPhone apps and 1 iPad app, they are great apps, but I am not making lots of money on it. It all has to do with marketing, promotion, publicity, advertising and are you good at that? Even if you are, you have a slight chance of being successful in this market. It is very very very very flooded.
If you go into writing an app because you think you are going to make lots of money, you have a .00001% chance that that will happen. And I think that is an optimistic percentage chance.
the guys are right - to be making money is very tough as its a super competitive market and the standard for apps is pretty high.
There was a really interesting thread on HN a while ago about developers making money - its quite an inspiring read to see what people have done/tried to make additional income (some of which work, some fail), but difficult not to get carried away thinking that you could start making money in an instant