Building your own database of keywords is one of the best ways to literally improve your data and get a better approach to ASO. http://asoagency.com/
our ASO keywords are the keywords and phrases in your app that make it possible for people to find your it via app store search engines. An app that is well optimized for the search “speaks the same language” as its potential visitor base with keywords for ASO that help connect searchers to your app. Keywords are one of the main elements of ASO basics.

We need to know how people are looking for your app, in order to make it a lot easier for them to find it — otherwise, they’ll land on one of the many other apps in the App Store search results. Implementing keyword ASO will help your app rank above your competitors.
This is why developing your own list of keywords is one of the first and most important steps in any ASO initiative. Keywords and ASO are directly connected when it comes to running a winning app search marketing campaign. Because keywords are foundational for all your other ASO efforts, it’s well worth the time and investment to ensure your ASO keywords are highly relevant to your audience and effectively organized for action.
So what to do with all your ASO keywords? Keep all the relevant keywords and delete those irrelevant keywords. Congratulations! You’ve just created a baby keyword database.
Remember, to keep them in the family. You may use a spreadsheet, categorize them, so it would be easier for you to use them for other related apps. You may divide your keywords into small, manageable groups of related keywords, so you’ll cut down on your workload (significantly). The number of categories will depend on the size and complexity of your offering. These categories will prove helpful in mapping out your keyword strategy and can also fall in line with your buyer personae and buyer’s journey stage segmentations.
OK, so you already have a pretty considerable keyword pool, organized for efficient implementation. Remember, just because your keywords are relevant, this doesn’t mean they’re strategically viable.
With this in mind, it is also essential that you filter out the impractical and illogical keywords. For ASO Strategies, a keyword with high difficulty score would be impractical. There are simply too many bigger players already entrenched around that phrase. We could never compete with the likes of that, please bear that in mind.
Also, you may want to stretch your pool of keywords include a bank of variations. You can use modifiers like “trending”, “top,” “new,” “next,” “best,” and so on. This is all depends on you. If you’re good with Excel, you’ll probably want to build a macro to help you with all of this.
I just hope that you don’t misunderstand me – a great keyword strategy is not a one-and-done ASO solution. ASO is an infinitely complex discipline. And without this type of keyword database, you’d be hard-pressed to get to anywhere. This is the starting point, and with it, the sky’s the limit. Good luck!