You can do this using the position settings available here. (remember that you’ll need to be logged into your account for this type of links to work).

As we mention in our app's description, we're currently able to provide menu placement for the 10 free Shopify themes, for both desktop as well as mobile devices:

Of course - this meaning that the menu / header of these themes hasn't been customized to such extent that makes our placement not work. We'll soon add support to other themes as well, in the meanwhile you can ask your developer to place this snippet of code in the desired location.

<div id="vitals-currency_converter"></div>

Somebody experienced with HTML / CSS should be able to easily position this in your theme's menu, in order to work well on both desktop as well as mobile devices. We can also provide this as a paid customization service - for a one-time fee of $20 - contact us if you need our assistance.