How to rank high in app store?
Downloads and good reviews get count there. So try to to get some downloads as quickly as you can, tell your friends, co-workers as a start.
Approximately 1.5 million apps available for download in app store and apps downloaded from the app store from July 2008 to July 2015 was 100 billion. Various criteria and methods have to used in order to rank the website like good app review, downloads. Another is punch a creative app description for higher ranking.
I don't know much but count of downloads and good reviews do get count in ranking.
Get more traffic, and share your friend circles.
You need to get sales for your app to climb the rankings.
Putting the most important keyword of your app in the title
Optimizing your app icon and screenshots so it can grab attention
Using related keywords to your app in the description