How to make my application being found by the keywords?
You may take account for some nuances with the keywords selection. Here's, what can happen and what you need to do if they appear:

NOT FOUND STATUS
? This happens if an app can't be found by our users among TOP-250 apps for the desired keyword.
! Try to choose another, more detailed keyword by which your app is among TOP-250 on a certain market.
*Note: if you see that your app is ┬źnot found┬╗ by exact keyword but some installs were already delivered, it means that some users found it but most of them didn't. It may happen due to changes on the market, such as appearance of new competitors (as an example). You may try this keyword in some time again, but first, use more accessible keywords to promote.
OUT OF RANK STATUS
? It means that users can't find your app with keyword you've chosen.
! You can choose powerful keyword to track your positions but remember that you can promote your app with long-tail keywords first. After your app will be find by the users via long keywords you can start to choose short-tail one and become higher in rank.
*Note: if your application is fresh it is better to promote it via package ID in order to make it visible on the market. Since your application freely appears in searches you can start to promote it with the keywords and get target organic users.