How to handle responsive positioning and scaling?

The options under the main display - doesn't apply to Android - except for the Heading part - so what you tick there is ignored.

On the Android side I don't think you're going to fit correctly without stretching or black bars on every single device - especially now with the foldable screens and odd resolutions.

It depends on your app and how many frames you have. If it's just one frame, then you could have a startup frame that reads the the width / display and then jump to the frame that best matches that. i.e. if width < 1080 - goto frame 2 etc. I think the Android and the Android+ objects can do that. And each frame can be its own size. If you have lots of frames, you'll have to decide on a compromise. You're either going to make the game to fit the smallest size - with empty space around it on larger devices - or you'll have to stretch it / use black bars.

To give you an idea - Amazon accepts these sizes as screenshots:

800 x 480 px
1024 x 600 px
1280 x 720 px,
1280 x 800 px
1920 x 1080 px
1920 x 1200 px,
2560 x 1600 px

I use 1280 x 720 and then stretch to fit - that also covers 1920 x 1080 because it's the same ratio. So a circle on my cell phone is an oval on my tablet. But the players don't know that. They would think that I designed it that way - the screenshots show it that way at Google - because they give you different options for cell phone screenshots and tablet screenshots.

This site may help you decide: Please login to see this link. .

I'm no expert on phones (foldable screens? never heard of such a thing! :o). But my guess is that if you focus on 90% of users without fretting about every outlier, you'll probably find that there are just a few basic aspect ratios in use, most of which are relatively similar. If you "sort by popularity" on the above link, it seems like 16:9 will cover you for the top 10 or so most popular phones. They're all either 16:9 or ones that look weird but are actually very similar (eg. 40:71 = 16:9.01)

So I'd say use 16:9 as your base. Then worry about the outliers after.

640x360 is the most flexible resolution for 16:9. It scales in multiples easily to all major resolutions:

640x360 1x
1280x720 2x
1920x1080 3x
2560x1440 4x

etc.

In the event of an odd resolution, you would default to closest multiple base resolution, then just stretch out the borders of your window without changing the scaling. Some graphics outside of the regular play area would make this look natural. Here's an article about how ludicrous did it: Please login to see this link.

It's for unreal 4 but the same idea could be used in fusion.