The name of this application is called Marvin Sketch. To download it head over to the website www.chemaxon.com. You will need to register an account first, so click the register button on the top right. You will need to confirm your email address, so after you register an account with Chem Axon open up your email and click the link they send you.
Now that you have an account set up with them go back to the website www.chemaxon.com and go under the "Product" tab on the top left and under the "Desktop and Web Applications" tab click on Marvin Sketch; then click "Download Marvin".
Be sure to check the box that says you accept the license agreement at the top of the screen; then scroll down to select which operating system you have as shown in the screen shot below and then click on "Download Marvin Beans".
Once the download finishes you may need to update part of your computer. If you need to update something on your computer you will be notified when you try to install the app you just downloaded.
Once the download is completed open the app called Marvin Sketch, which should look something like this.
You can use the icons on the bottom to make a ring structure, the icons on the right to add any element on the periodic table, and the lines to the left to make carbon chains.
Once you have a compound you want to know the IUPAC name of click on Structure > Structure to Name > Place IUPAC Name.
You can also use this app to show you the structure of a chemical if you type in the name. To do that just go to "Name to Structure" instead of "Structure to Name". Then type the name in and click on "Import".
There you have it! You can now name any chemical your Organic Chemistry Instructor has to throw at you.