Possible idea/Does it exist?

So I am on my computer all the time, like 10 hours a day, So! I was wondering if their is a program for the computer or for android, (probably would need both) but it would basically just display your smartphone screen on your monitor and you could see it, so if you moved the screen or did something you would see it on the monitor but also you could control it from the computer, for example you get a text, you see it on the side of your monitor, so you could use your mouse, click reply, and then type a reply. Assuming this would be via usb or something but I feel like if someone knew what they were doing it would be really easy to do since its mostly just adding a output and allowing mouse and keyboard clicks to simulate touch actions. I dunno! I think it would be really cool, and if it was in the app store would probably pay upwords of 20$ for something like it. Thanks for any info