Nice problem; I hope to have it someday.<p>First: I echo the previous posters urging you to reconsider the stock market.  It's low maintenance and is a nice way to diversify away from your business if you feel it's not sustainable.<p>I just reread your post and noticed the implication of "I do not want to invest...long term like bonds or property".  If you plan to need/use the money within, say, 5 years (preferably longer) the stock market isn't for you--so you're doing something right there by not wanting to go with stocks.  I just think that people are urging you to think long term<p>That said, you want to make money fast short term.  I will add to those pointing out that this is generally difficult.  However, you do have at least one good idea proven to work at the moment: your success in the app store.  Your best bet to make more money quickly in the short term is to attempt to scale what you're already doing.  Note: this may not be possible.  I still think it's your best bet given the constraints you give.  You're worried about time investment, but that's nothing that hiring someone can't alleviate (but not remove).<p>Finally, care to answer a few questions about your success?  I imagine you're hesitant to share more identifying info, but how about things like what you do for marketing?  Or how much time it took to get to this level, how many apps, and how much time it takes?