The first and foremost thing to do is to understand your target audience. Once that is done, you have to figure out the competition and where does your app fit

The first and foremost thing to do is to understand your target audience. Once that is done, you have to figure out the competition and where does your app fit into the whole scheme of things. Once that is done, have a good marketing strategy to pitch your app for the appropriate audience. For this process, blogs such as LH come into picture (if you know that your potential users "do" follow those blogs). Investing a little in SEO and promoting on FB is also not bad option. Also, the success of the most apps depend on the first impressions, usability and word of mouth from peers :)