Yes, third-party apps are the best. They make what FireStick is truly worth. I have been using third-party apps for a while. You may want to try cool FireStick apps list I came across recently: https://www.toptvtricks.com/best-fire-stick-apps/

These apps will have to be sideloaded onto FireStick. By sideloading I mean manual installation. You are not going to find these third-party apps on the Amazon App Store.

I suppose you already have the Downloader app. This app is used to sideload apps onto firestick and fire tv. If you don't have it, you may get it from the Amazon Store (yes, Downloader is not a third-party app, but it is a great utility to have)

You will need to enter the URL in the Downloader app for the APK file. To type long URLs, you can always use your phone as the remote with the Amazon FireStick Remote App: https://www.toptvtricks.com/firestick-remote-app

Also, some of these apps may not respond well to the remote commands as they have been designed for touch devices, like your Smartphone. In that case, you can use the https://www.toptvtricks.com/mouse-toggle-fire-tv/