@Will M As @Don Simms states, it should be installed on your TV by default. Depending on your TV model (the you have not posted), you may have to scroll right to look at ALL the installed apps on your tv.
That's correct you can't add any app you want just ones that were written for LG smart televisions. May I suggest you contact Les Mills and see if they have any plan to have an app developed for LG smart TV's.
Thank you so much for this fix! Did the trick for us - gone from 0.5 to 100Mbps after disabling Screen Share (press the sources button - took me a while to find this as it's not in the Settings) and restarting the TV. Never would have guessed!