Please read the Answer from @sascha here, How to work with CSS Helper Classes? - YOOtheme .

Update:

Thanks for the feedback.

YOOgards

@mustaq,

Thank you mustaq! I had 2 different modules before (one for display on phone and one for display on desktop) where I had used the
Module Class Suffix: hidden phone
in the module for desktop display. However, that didn't work. It showed up on my iPhone anyway...

SOLUTION
Now I have one single logo module but I have hidden (hidden phone) only the text part of it almost according to sascha's example, like this:

<h2><img style="vertical-align: middle;" class="size-auto" alt="logo" src="images/logo.gif" height="60" width="109" /><span class="hidden-phone" style="color: #666666;">&nbsp; The text that is hidden on the phone here</span>  
</h2>

What I wanted to achieve was to hide the text (company name that is too long to be displayed on the phone) so this works!!

Greetings
Anna

Torry... I am with you the documentation for the Responsive code is HORRIBLE and impossible to find! Someone PLEASE make some helpful docs so we can use these features efficiently and not lose hours reading hundreds of tech posts simply to get frustrated!

Hello Anna,
Could you tell me where you found the "hidden" commands on the yootheme website? I've been looking for this documentation for the Nano2 template, but cannot find it.

Thanks,
Torry

@torrymills,

Please could you +1 my question to help my chances of getting a solution? (To do so you need to go to the top of the page and press the + to the left of my question.) Thanks!

Here's where you find the CSS helpers for Nano2. It would really help if YOOtheme's blog had a search function!
http://www.yootheme.com/blog/2012/06/12/warp-gets-responsive

Greetings
Anna

Thanks Anna! I +1 your message. Hope it helps you get the answer you need!

Torry

@philip.madsen,

Thank you philip. However this is all YOOtheme with the new responsive feature in Nano2: Please view this link (that I also posted above in my reply to Torry):
http://www.yootheme.com/blog/2012/06/12/warp-gets-responsive

So, I'm still hoping for a solution...

Greetings
Anna

Thank you Johannes,

That is how I did it before the new responsive Nano2 as well. However, since Nano2 is fully responsive (Warp 6.2) it now works differently. And it's great (except for my problem). Here you can see what I'm talking about (especially the part about CSS Helper Classes):
http://www.yootheme.com/blog/2012/06/12/warp-gets-responsive

So, I'm grateful for your attempt to help out but I guess I'm still looking for a solution

Greetings
Anna

The hidden field is most likely a theme other then yootheme field. Such as mobile Joomla and for it to work with the yootheme you will have to use a yootheme. You will have to style it the way you need it to work if this is the case.

Thanks
If you find my answer acceptable please +1 my question to help my chances of getting a solution for other issues?