There is no need to install RogerRoger! You can use it on any computer with a modern browser and internet access.
Some browsers like Chrome will have an option to add RogerRoger to your programs for quicker access. If you see the first icon in the address bar of your browser, you can install RogerRoger as an app.
If you want to use RogerRoger on a mobile device, please read this.