Hi @BSDAOM778 It seems like the app has injected the code in your theme and you need to remove that code so that your mobile menu can work.
As sometimes 3rd party app inject code in them theme so that they can show their stuff on the live theme and even if you remove the app from shopify, you still need to find the code that the app has injected in your theme and remove it so that your site can start working fine.
If you are unable to find the code and still facing the issue then I'm happy to do this for you, let me know. I can remove the unwanted code for you and fix your menu.
Hopefully it will help you. If yes then Please hit Like and Mark it as solution!