No matter, whether the app is inside a folder or not: you can tap the app long enought to get it hovering. Then, you can drag it around.
If you now drag it to the border of your screen, really the very border (left or right), the page will change while you’re still dragging the icon. Then, you can just drop it there, or drop it into an existing folder or drop it onto another app to create a folder.
At least I tried with mine just a minute ago and it seems to be working that way.