Hi there, before increase your app visibility, you should optimize the following aspects to increase the download rates:
· App title - Make sure your app title unique and attractive.
· App icon - A better icon can increase your downloads up to 560%. keep your design simple and eye-catchy.
· Screenshots - Show off the best features of your app in the first two images. According to research by Storemaven 60% users won’t swipe past the first two screenshots.
· Description - To capture a user’s attention and keep longer utilization, your app description has to be precise and make the right direction attract users. So make sure to highlight your app features and advantages in the first line.
Get positive app reviews(http://www.reviewapp4u.com/?from=cr-chris ) - 95% users will take the app reviews as one of the most important reference factors to judge the app, and most people prefer to download an app which has much more positive reviews. With great reviews, your app is going to be in great shape to rack up downloads and beating out the competition.

Then you can increase your app visibility with the following methods:

Apply for Awards
Participating in app awards is the most recommended channel and I would highly suggest you take advantage of it. It can give you tons of press, exposure, reviews and plenty of downloads.These are many famous app awards sites, such as Appy Awards, Best App Ever Awards, AppCircus competition, Apple Design Awards, etc.

Get featured on App Store
According to App Annie’s Report a feature for a game can lead to a 140% increase in downloads and for non-games to a 25% increase. Apps which with the following features tend to be get featured :
· Great app
· Universal app
· The user experience should be top notch.
· With compelling product page: video, screenshots, a good name, and a quality description.
· Have good App Store Optimization(ASO): app name, keywords, and category.
· New apps and apps with significant updates

Cooperate with influencers
Most people like to follow others and be influenced by the words of some celebrities or well-known business people - having high-profile Facebook pages with 100,000+Likes mentioning your app is a huge win. Reach out to organizations whose goals align with yours, and give them a compelling reason to mention or link to your app on their page.

Hope those methods are useful to you.