What make people to download a Mobile Apps?

Influence Users to Download your App by addressing the below

Installing an app does not require that much of time (based on the app size and the bandwidth you have), however using the apps regularly does need a research.  Users do checkout the below options of a mobile app before using it regularly.  So checkout the question a user who would download and use a app would ask.  

a) What is the enabling feature an App provide?
b) Which version of Android / IOS is supported?
c) What is the size of the app??
d) How many users have installed it?
e) What is the average rating of the apps?
f) How frequently it’s getting updated?
g) What is the Content Rating?
h) Does it contain advertisement?

Users may not ask all the above question, however there would be combination of questions which enables to make a decision.  

There is a most important and primary aspect for your installation which is UI (User Interface), User will look for an app icon and the screen short of an app, if this is interesting then User would download the mobile app.