how to solved Apex Applications manu bar may not show on mobile device

You can solve this problem by doing this Dynamic Action.

1. Create a Dynamic Action in  0 page.

2.Set Event  : Page Load  Execute JavaScript Code

3. Set Action : Execute JavaScript Code Now you can try on mobile device

4. Then copy pest this JavaScript  Code :

$(".t-Header-nav").removeClass("t-Header-nav");

Now you can try on mobile device.