OS Yosemite Duel Screen / Split Screen Function

Is there, or will there be a way to use the Split Screen function in the new OS Yosemite with ANY app or program? I really want to use iTunes and Adobe Photoshop together on my Macbook Pro as I have a habit of using them both for work, same with Adobe inDesign etc. I know there is a app called something like "clinch" that does the same, with any app or program, etc but I really wanted to use the one that came with the OS this year. Will there be plans to make this update happen? or am I doing something wrong? It just keeps saying that its 'not available' when I try to split screen / duel screen say safari and photoshop, or iTunes and indesign. Help and suggestions would be much appreciated ! x