When you go through a Regular Start, you can choose which layouts you want to include from your FileMaker solutions. There are various reasons you might only want to include some of your layouts to build a native app.
The simplest thing to do on this screen is just to click "Add all" and proceed, safe in the knowledge that you definitely haven't missed out anything your app needs to work. This is a good thing to do if you are going to target several platforms from a single compile. However, you might want to make your app a bit smaller and more nimble by only including layouts it really needs.
Some Android phones are small, with limited memory, and the smaller you can make your app, the better it will perform. In the Event Management app, there are a number of layouts that duplicate functionality, for different devices. If I was only targeting Android phones with my compiled app, I'd be smart to only choose the Phone layouts.
I can do this quite easily by filtering by the keyword "phone" (1) then choosing "Add All Layouts" (2). All the phone layouts will be added, and nothing else.
You can also select individual layouts you want using cmd/click, and then use "Add Selected Layouts" to use only the ones you have selected.
If you have built a solution that already runs on iOS, then choosing the layouts created for iOS will work well here.
Your solution may not have been built with Android phones in mind. If that is the case, at this point you might need to consider how well it is going to work on a screen size of 240x320. Maybe you will need to do a little reworking of your solution to make it fit...
While it might be a good idea to only include layouts your app needs to work on a specific platform, you must remember to include every layout that is visited by any script in the app. Layouts can be visited by scripts even if they don't visibly appear at any time.
If your solution has been designed for desktop only, and you are now building for a tablet or phone, its quite likely its not going to look great without some tweaking. If your app has been designed for iOS (FileMaker Go), it has a better chance of running well on Android.