Show HN: Stock Bubbles app, advices?

A few weeks ago I got an idea for a more interesting interface to check the stock market. The huge list of symbols in a table view that are either green or red (the same red and green whatever the gain is 0.1% or 10%) is not really cool for fast scanning, nor fun to use.

Since I happen to be involved with an iPhone and iPad devleopment company here in Sicily since a few years, as share holder and "advisor", I suggested the idea to this friends of mine. As there was no really development bandwidth to do things like this, as they mostly work for other companies creating applications for the editorial market, I suggested to do this in the spare time, and check how this could work as an alternative to just providing services to other companies.

So one of the developers, and my girlfriend that is the graphic designer in the company, started working at this, and after just a few days the app was ready.

http://itunes.apple.com/us/app/stock-bubbles/id417945202?mt=8&ls=1

This guys read hacker news every day (this was one of my first advices), but never participate with actual comments. I think it's a shame that they don'ttry to directly sell things on the app store most of the times, so please can you provide some suggestion to this guys? What's ok and what's wrong with Stock Bubbles, is it too much a small market to create a viable business model? Does it makes sense to create such side projects with just a few days of work of a few poeple, or it's better to invest months developing an application even if it could not be a success at all? (while doing work for customers will pay less but will pay for sure).

Thanks for any feedback, the developer of the app is 'artix' here and will reply to all your questions. The app is free, but with an optional in-app purcahse to unblock the configuration screen, but there is no need to buy it to check how it works and to provide useful suggestions of course.