Have you built a list of relevant keywords for your app? If yes, just use them in the title and the description. If no, then build it and use it.
Your app would appear higher in the search if you would have a lot of downloads. You can start promoting your app somewhere apart from Google Play (social media, landing page, e-mail etc.). This will increase the number of downloads and if you are using the right keywords, your app would become more and more popular.