I put out an app a couple days ago. The idea is for house hunters, refinancers, real estate pros, etc. to be able to get their info on the go. It currently includes:
-Basic mortgage calculator. Yes, I know it's like the 5th one on the market. But wait, there's more!
-Real-time mortgage quotes - pulls data from Zillow web services
-Housing value estimates - also pulls data from Zillow web services
It's free; I'm showing a couple adsense ads in the mortgage/valuation result windows. I'd love to be able to avoid the webview and integrate it all into the android client app, but then I'd be stuck using admob sdk, which pays about $.02/click, compared to adsense, where so far I've picked up $.50/click. (I don't think admob has high-end traffic like mortgage stuff to up the revenue per click).
Anyway if you want to see an example of integrating web content with regular android layouts, or another scheme for making money off a free app, or if you just happen to be looking for a house, check it out. That is, if you're in the US. That's the only country I have data for so I restricted it to the US - I didn't want people getting frustrated and giving me bad ratings.