If you use gantry 5 for your website templates, an extremely useful feature, available via Bootstrap, is the collection of responsive utility classes that can be used to help tweak layouts by providing a simple method of showing or hiding modules. 

Insert the following module class suffixes into your module settings to show/hide a module for a particular mode.

As an example, if you wish to have a login module appear on desktop and tablet devices, but not necessarily phones, you can place hidden-phone in the Module Class Suffix field. This will allow the module to remain visible on any device displaying the page at a width above 768, allowing you to maintain the look you wish to achieve across multiple device types.