Is there a way for me to create a custom menu when the screen shrinks down to tablet/mobile sizes?

Here's my situation. I have a main navigation set up as well as a top bar secondary menu. The problem is that when on tablet or mobile the top bar menu disappears and there is no way for that content to be accessible. Can I either force the top bar menu into the main navigation once at a certain pixel size? Or do you know of a way to create a custom menu for when the screen size reaches the first responsive width?

Thanks, - Nic

I actually found a previous post that discussed the option of a \"mobile menu\" within the menu structure. Sounds like this is already an option. The issue I have now is that this theme is no longer available on the Envato market.

Is the theme getting an update and will be reloaded on the market or is it permanently unavailable for future updates?