App Store Optimisation Discovery Channels

Optimise App to Get Discovered In App Stores & Search Engines
Your app or game has two main ASO discovery channels. They are within app stores, like iOS App Store and Android Google Play Store, and the search engines.
When people search directly in Google, they will see this when searching for "Angry Birds".

Or if we broadened our search to "casino app", you might see this result...

Now, those channels have different algorithms to rank apps. Therefore, you have to optimise your app for each channel. Google Play and iOS App Store are very different places. They provide different input elements and use different ranking factors. Obviously, the same applies to search engines.
As you can imagine, the competition can be different across the channels. That's because businesses don't always launch their app for both iOS and Android. So you might find it easier to rank well in one store and not the other.
Another thing to consider is the country and language your app is available. A smaller market in a less competitive country with an uncommon language will make your app launch and climb to the top a lot easier. The opposite is also true. But remember, there has to be a desire and demand for your app in any given situation.
So, to rank well in the app stores and search engines, you should optimise your app for each market. Going broad and cross channel with the same metadata is a big mistake.
First of all, you will want to start with the basic elements of app store optimisation. They are your app's name, subtitle, descriptions, keywords, categories etc. Many elements are the same, and the channel's algorithm will often look at the same things.
Even so, you'll need to optimise them differently. For example, optimising the description is crucial to ranking in Google Play. You will want to focus on the keywords and phrases. On the other hand, Apple seems to ignore the description as a ranking factor.
But that doesn't mean you should neglect any fields because the search engines are looking at the information. We are not simply optimising for people... we are optimising for bots too. If we were trying to attract someone, we would concentrate on a few words, pictures and reviews.
But the search engines use that information to populate their SERPs. As you can see in the examples above, the search terms are bold in the listings. They are highlighting to the user that what you are looking for is in the link. Also, the elements carry weight in each app store algorithm.
At any rate, those basic elements are required by the store before you can launch your app. So fill them in as best you can. Most of them will not change until you update your app. And this is the main difference between ASO and SEO. Unlike SEO, ASO changes affect the app store immediately as you update your app. SEO changes take some time to produce an effect.
So, if you make a mistake during an update, you will see the results instantly. For example, you may have changed or accidentally deleted a keyword or something like that, and suddenly your metrics plummet. Then you can either revert the change or add the keyword back in and then update your app to see your metrics bounce back.
From then on, it's an ongoing game testing and measuring your app store optimisations.