Using smartphone as a remote mouse is very helpful as it during presentations, where you want to control sitting at a place instead of much inefficient way of going and changing slides again and again. Apart from this, if you're working in café, you'll need to carry a mouse, keyboard or any other accessories along with your laptop but with smartphone you can skip all the accessories.
Now, you can use smartphone as remote mouse while in café or during a presentation or if your trackpad isn't working. And yeah! You can activate multi-touch function by checking the option from the settings in the mobile app.
You can also use smartphone as remote keyboard by clicking the on the keyboard icon on top right corner of the app after you have connected your Android to your PC. Control music, switch between apps, type, and navigate to menus using Android as mouse and keyboard apps and iOS as mouse and keyboard apps.