Besides those reasons mentioned in other reviews...

This newest version’s interface is still not acceptable to use especially when compared to a competitor — StockMarketEye. I normally have over a dozen watch lists to monitor and this app really makes updating a real task. I use StockMarketEye (and its not free) almost exclusively. StockSpy’s NEWS feature is superior, but if you want STATISTICS including excellent graphs, StockMarketEye can fill two full widths of your screen with information on a stock and you have full control of what statistics to display and where to place them (by dragging and dropping). As for StockSpy, I purchased this app over a year ago and when I saw it was updated i seriously have tried the new version this week inputting 11 watch lists that I currently use. And I am still disappointed. The upgrade to the Pro version maybe helpful to you, but after spending if I remember correctly around $30 for the original (and now free) adding $10 more for the Pro version added nothing I really needed. I do admit that because it is now free, StockSpy may be enough for your needs.

Aviano Saint about StockSpy Realtime Stocks Quote