Is it worth investing in ASO?

Yes, ASO is becoming as important as SEO. If you invest in SEO then you should also invest in ASO especially if you want to run a successful app business. One of the main reason to invest in ASO is because it's a long term solution. You can't always use paid methods to increase your app downloads. Organic search would usually give you users that are more loyal. Here is an article from Forbes that can help you understand the reason of why you should invest in ASO 7 Reasons Why Your Business Should Invest In SEO.

Different categories require different ASO techniques, here are some of the best techniques that you can implement in your ASO strategy:

- Add Keywords into the title
Although, the exact ranking algorithm in app stores was (and probably will) never made public, many app marketers could recognize that the app title is one of the most crucial factors for ranking. So make sure to include your most relevant keyword into the title. However, it should stay readable and clear!

- Avoid too long descriptions
Users do not read eternally long full-text app descriptions. They immediately want to know what your app is about. So make sure to start with something getting their attention and then try to clarify your apps features in a plain and preferably short way. Better concentrate on the most important features and keywords.

- Observe and Respect User Reviews
User ratings and reviews are very important aspects for your apps performance in store. Although there are bad reviews, you should answer them as fast as possible. Positive reviews, especially, should get highlighted.

- Monitor your app & Try new things
As App Store Optimization is an iterative process, optimization never ends. Positive results might not be visible immediately. So make sure to continuously monitor and optimize your app and app store rankings. As every apps path of optimization is different, just try out things and document whether it worked for your app or not.

Also here is a link to our ASO Guide, which tells you the most important principles and facts about App Store Optimization.
App Store Optimization Guide » App Radar the ASO Software

I hope this helped.
Keep Optimizing