Cross promotion is one of the efficient way to generate app installs and reviews freely.
Once you published your app in Store, you can market it with cross promotion with other apps by installs and reviews exchange. It is free while it is still hard to find that publishers like you. You may try some Cross-promotion networks (CPN), Facebook group or exchange forums.
In addition, I would like to recommend some other ways to reach the market.
Press Release will obtain very positive results thanks to the “newness” factor associated with Apps. You will post your app features on the press release sites, related column, etc.And if there are many persons catching your post, they will comment. You will know the feedbacks then.
Social media networks
Having a Facebook Page for your app is a must-have where you can ask them how they like your app designs and features and any get feedbacks. Also, you can share any news about your app, etc. However, remember not to make your posts only about your app, though. That is boring. It’s like talking to someone at a party who only talks about themselves.
Buy app rating & reviews
One app can get reviews, it must get installs firstly. Reviews provider like BestReviewApp will guide real users to install app, play and reviews it with ratings. This method will rank app top in a short period. At the same time, the traffic is from real users which is organic. It will Not have bad impact on apps.
Run advertisements on some Android forums, Google ads or social media, it is one common method for publishers to promote app. But you know, there are many people browsing Facebook, Twitter, Instagram, etc. There are less targeted audience for your app. CPI would be the best ad payment method.
Higher ranking is extremely helpful for app visibility. App can get installs from users directly via download link. Or drive install via keyword search. The former method is straight forward install amounts singly. While latter one aims at helping app ranking in App Store search results. Keyword optimization also will guide real users to install the app via targeted keywords relevant to your app.