From all that I've found while researching this it appears that the Westinghouse Smart TV's are limited to the Factory Installed Apps and no more can be added/downloaded, etc. This is common with the less expensive tv's & many other consumer electronics, including many cell phones. I'll post a few pics from people asking similar questions on the technical suppourt sections of a few websites.
I have a 3D Plasma Samsung and it's "Smart" features aren't very impressive. So I have dealt with this very situation and know it's a bit frustrating. Fortunately, there an easy solution.
Here's what you must do if you want more features/apps aside from what you've got that's pre-installed on your TV:
1.) You must hook up another device to your TV to enjoy these features, you'll be using another device with a separate remote control but it'll be displayed directly on your tv screen, plus you can program the remote to operate your TV as well so only 1 remote is needed.
Pick up an inexpensive "Smart" BluRay or DVD Player that has a lot of apps to begin with, many are likely to have what you're looking for already installed from the factory, just get one that allows you to add/remove apps freely, a sales associate in any electronics department should know the features of the different units so tell them what you want and they'll see to that you get the right one. I'm including a photo of one from Wal-Mart that's inexpensive, just as an example.
2.) You can do the same things and ultimately much more if you don't mind using a Video Game System. I'm sure if you don't have one lying around a friend or family member does and these are capable of so much. I have used a Sony PlayStation 3, XBox 360, and a few 3D Smart BluRay Players- I like the video game console option best personally so I can add all kinds of stuff like music and pictures, etc. The Game Systems have large hard drives so lots of storage space for everything, including new apps and you'll have Plenty of Space for downloads like TV Episodes, Movies, & More.
3.) You can use a Roku Device or Amazon Firestick as well, they're always evolving and you should check the Roku and Amazon Websites for the latest models plus the features and capabilities they offer. Some have a monthly subscription cost but you pay 1 price(that's actualky quite low) and this gives you access to many of the most popular apps like Hulu, Netflix, Etc. and many more for one price and you don't have to make and keep up with individual accounts and passwords, billing info., etc. for all of them so this is a convenient option that's inexpensive.
You have a few options, I'd say get a good used Playstation 3 Check with people you know and I'll bet someone has a good gaming console that's not in use and never will be again(they're really cheap these days since they're "outdated" but still have state of the art technology to handle anything needed for the purposes we're talking about and much more! So, before you shop around just ask a friend, family members, maybe one of your kids, nieces, nephews, their friends, etc. if they have one they'll donate and show you the basics of using it. If you already like video games and have a newer gaming console like a PS3/PS4 or XBOX 360/XBOX ONE already just use it. I use mine instead of my Samsung or Toshiba 3D Blu Ray Players because of the convenience and more functions/options they offer.
A $40-$50 Smart DVD Player is all that's necessary, but you may want to explore these other options depending on your personal preferences!