If you have an iPad or iPhone, you know that to move an application on another screen or add it to a folder that is fast enough. You should gently press the icon until it starts to move. It'll just move it.
This technique works well unless you have tens or hundreds of applications. The handling of applications and files becomes tedious quickly. Obviously, you can reorder your applications from iTunes.
However, if you wish to make changes from your iPad or iPhone, there is a simple trick. It is to use your files. Two instances where this trick can be helpful: when you want to move applications from one screen to another and when you want to add more applications on the same theme in a folder.
Here's how: