If you want to prioritize downloads of your mobile app instead of visits to your mobile site, you should:
run an app install ad
add a sitelink extension
include the word “Install” in the ad text
add a call extension
Explanation:
Mobile app installs campaigns are geared specifically toward getting more people to download your app. AdWords can help customize targeting, keywords, and ads based on your app ID and other information. You can easily gauge your campaign’s performance by tracking installs as conversions.