A quick search on github.com (https://github.com/search?utf8=%E2%9C%93&q=shazam) lists a lot of implementation related to it. Bad that they are running behind a single guy. May be their implementation is exactly same as what is posted on the blog.
If you are in a financially constrained situation wait for some more time at least till the company goes to IPO. This will save you financially and also will help you in your next venture with more freedom. Since you asked about joining another company, I have a feel that you need to wait for some more time till you get the complete hope of starting on your own. Regarding staying on the same company, talk to an advisor/mentor who knows about the market in your region. All the best on your next venture!
I'll be at my 57. I would love to build a vintage home in the far south of India and maintain the agricultural lands that I own. I would love to do anything myself without anyone's help. And I don't want to be a coder by that time but I would love to teach others by that time. I would have explored at least 50 countries by that time and also might have finished my second book.