Once I find out the keywords that better fit for my app what should I do?
Put them in the description 3-5 times and???
Is there something more that would help increase the ranking?
Yeah ,do the link building with the keywords
put them in the package name
the name of the app.
In the past the package name used to help, but today I don’t think it does.
Hi Ankit thanks. What do you mean link building with the keyword?
Adding the app domain + keyword to facebook, google+, forums ecc?
Any suggestion on how to use keywords besides in description? Or how to link building with keywords?
write articles with keywords, have reviews with keywords(reviews actually help!)
Put 3~5 keywords in description is beneficial toboost app ranking.
But, when you choosing keywords, besides relevance, you should also take competition and traffic into account.
Competition: It has no much impacts if your app is ranking beyond #300 for a keyword even it gets billions of searches a month. Because nobody is willing to scroll the phone to find it as he has to achieve that far in search results. What should you do? Just look for keywords that you can rank in the top 10 and make it in app title and app description.
Target keywords with low competition and lower search volumes first. After gaining the initial momentum, start using keywords with higher traffic and reasonable difficulty.
Traffic: You also need to choose the keyword based on the number of searches it gets.
Optimize reviews
The keywords used by your app users in the reviews can be used by the app keyword ranking algorithm to rank your app. The more the number of positive reviews you have, the higher your app is likely to rank. The keywords used in the reviews will also help your app rank in search engine results, thus driving more traffic.
Tips to optimize your app store keywords
[ul]
[li]Don’t use spaces, use commas - The App Store algorithm reads both spaces and commas as separators.[/li][li]Omit the connectors and save some spaces [/li][li]Use digits not words - When you use “5,” the App Store looks for “5” and “five”.[/li][li]Don’t repeat keywords [/li][li]Plurals can be used for App store optimization[/li][li]Use shorter keywords[/li][/ul]
Ways to get keywords:
[ul]
[li]analyze competitors[/li][li]Use Keyword Tools to Find Best Keywords[/li][li]Rely on app reviews[/li][li]Check app descriptions[/li][li]Search suggestions[/li][/ul]
For ranking your app or game and getting installs & reviews, i recommend KeyApp.top - Android keywords promotion, they provide keyword install, US install and reviews for a very low price
Register by using this link KeyApp.top - Android keywords promotion and you will have a Free $20 bonus installs to promote your Apps/games, up to 500 installs for free ! 
If you place your selected keyword into your title, that will help a lot. Especially when your app is not visible with that keyword.
Also place your keyword 4-5 times into your description, mainly at the biginning of your long description.
When your app is visible with that keyword, you can run keyword install promotion. We offer this for $0.10. You can get some discount for your first order.
Website: Android Installs
Good luck!
Hi there, you should put 8~12 keywords in your description, which are beneficial to increase your app ranking, you can aslo put the important keywords in your app title, which can increase your app ranking by 10.3%.
Based on my experience, the most efficient way to boost app ranking is buying keyword search installs, which can boost your app ranking in 8~10 hours. It’s really worth to have a try.