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.
Creating blog content is a very useful and effective way of consistently building content on a site. When creating blog posts, it's a good idea to do some keyword research to figure out what it is that your audience is interested in and searching for online. Also, be sure to research competitors, forums and social media to narrow down on topics for your blog.
Always disclose your affiliate relationship. Most visitors will probably understand that graphic ad will lead to your getting paid, but if you write a review or use an in-text link as a recommendation, you want your readers to know that may lead to compensation as well. This ensures you retain transparency and trust with your readers, but also, it's required by the FTC's endorsement rules.