Be professional. When you submit a résumé, don’t type it in ALL CAPS and please don’t avoid the caps lock like the plague. Know how to use it without looking incompetent. Write in complete sentences with proper grammar. Of course, there will be exceptions, but even with the exceptions, you must keep it professional. You’re building their view of you.
The second (and cheaper) path assumes that you have the design and dev chops yourself to build your dream software. Naturally, it’ll take more time to get your product off the ground, but being able to bootstrap the development of your software lets you retain more ownership in your business and be more in control of your path, making this a lower-cost, but higher time investment to make money selling apps.
If you want to start small with a pretty basic email marketing software that will give you some room to grow, this could be a good fit for you. Campaign Monitor offers a free trial and then a basic service that costs as little as $9 a month for the ability to send 2,500 emails to 500 different recipients. Once you reach the level where you'll need the Premier Plan it starts to get more expensive, though. You'll be able to send unlimited emails to 50,000 recipients for a monthly charge of nearly $1,000. For more recipients than that, you'll have to get a custom quote.