That variable is only set to true if (1) you’re on the legacy templates; (2) you have NitroMobile enabled; and, (3) the following regex matches your user agent string:
Perhaps hold off as I’m still debating a switch over to the newer templates but haven’t had the time to tackle this just yet.
Saying that, I’m sure others would find that to be a useful snippet if it were working on those responsive templates. Server side would be my preference for this type of code.
I’ll add an item to our backlog to cover a new NitroScript variable that takes that updated RegEx into account. We’ll also ensure the built-in mailing list popup feature doesn’t trigger if it’s true.
Please be advised that we have made the necessary adjustments in the code.
Here is a summary of those changes:
The pop up window will no longer appear on mobile devices;
We have updated the regex to improve the mobile device detection and is now based on the one provided by http://detectmobilebrowsers.com/
There is a new variable accessible from NitroScript called {pageproperty[‘useragentismobile’]} which is a flag indicating whether the user agent (the customer’s browser) is a mobile device.
All those changes are available on branches Beta, Alpha, and Early Adopters.