Great. So what would you like to buy using Bitcoins and what do you have that you are willing to sell in return for Bitcoins?
Solve that and I'll admit you have a useful app.
Basically, EVERYTHING you now use cash for....
My buddy owns a convenience store. He already has an Android phone. I guarantee you that if this app were available, I could easily talk him into accepting Bitcoin for all purchases in his store. What does he sell? Milk, eggs, soda, cookies, candy, bread, newspapers, batteries, and on and on...
Someone owns a coffee shop. In Manhattan, some of the coffee shops are sort of "bohemian meccas of geek culture". They would LOVE to try something like this! And the geekazoid technoweenie customers would take to it instantly!
Ironically, at the other end of the political spectrum, in the Libertarian mecca states where militias live, and the Liberty Dollar is still promoted... Those guys would LOVE the opportunity to get an anonymous private currency into their hands! One that they can use for buying everything from milk and bread to grain and farming supplies. Anything to get the government OUT of their wallets.
Another friend of mine owns a Chinese restaurant. I know for certain that she would love to use something like this.
My friend in Columbus, Ohio owns the largest dance instruction studio in the Midwest. He wants his studio to accept Bitcoin. He's now asking me to help him get set up to do so.
It's really no different than setting up a private "barter club" for a local business networking group. What would the participants have to lose? Nothing. They'd have everything to gain!
I think that even the pot delivery man would take to something like this... if only to avoid walking around with loads of cash on their person!
There really is NO limit to what this could and would be used for.
And that means, more and more and more opportunities to use Bitcoin, and to earn Bitcoin.... due to an ever increasing online DIRECTORY of places that ACCEPT Bitcoin.... and places that SELL Bitcoin for cash....
Basically, everyone with an Android phone would pretty much become a "store" of one sort or another... and a customer too.