Summary
Being able to generate income from your apps is an important part of being an independent app developer. Sure, you can get paid writing apps for other people, but if you are able to generate cash from your own ideas, you buy sufficient time to make your own app ideas a reality. Don't be limited in your ideas; the sky is the limit for apps and there is still time to write that killer app that makes a real difference.
I wish you luck with your apps, and congratulate you once again on your choice of tool, and of course on your choice of cookbook!