Data show that over 75% users download an app by searching in the app stores, so you can boost your app ranking in the app stores to boost app downloads. And the most effective way to boost app ranking is buying keyword search installs, which can boost app ranking in 8~10 hours,then 1000+ downloads a day is an easy thing, and it will not cost you too much.
About buying keyword search installs, you should take relevance, competiton and traffic into consideration when you choose keywords. If your budget is enough, you can choose high traffic and high download rates keywords, which can bing much downloads for your app.
Besides increase app ranking, you should also get positive app reviews to increase the download rates, generally speaking, people will check the app reviews before downloading an app, and 88% users trust reviews as much as personal recommendations, potential users will be convinced when they see your app have gained many good reviews from your former or existing users and choose your app.
Here are some other effective marketing methods for u:
Promote your app across multiple traffic sources
There are several types of traffic sources for mobile apps, such as ad networks, real-time bidding exchanges, social networks and more.using just one source—or even one from each type—gives you too small a universe to be successful. You’d be missing out on valuable opportunities to identify the best sources for large volumes of loyal users. Then more people it reaches, the more downloads you will get.
Limited Discounts
You can offer your app for free or at half price for a period of time. but emphasizing that it is for a limited time in your description, social media posts, and other PR, plays upon the aforementioned perceived value factor.
Run Facebook Ads
Mobile apps are increasingly helping businesses grow. Facebook mobile App Install adverts enable businesses to connect with the people who are more likely to install your app, so you can get more people using your app. And you can target users based on various factors such as age, location, mobile OS and many more.
Hope those methods are useful to you.