Did you notice this on the Pure Chat FAQs
Sorry for the big type - just copied and pasted from their site.
What mobile support is available for Pure Chat? A Pure Chat iOS app is available for both iPhone and iPad. We currently do not offer an Android app at this time. Additionally, the Pure Chat chat widget is optimized for mobile browsers.
I've copied and pasted the javascript, but I don't see the chat widget on my website. Why not? In most cases this is due to no operator being logged in with a status of “available”. Make sure you are logged in and available, and then check your website again. If you still don't see it, refresh the page to ensure you aren't looking at a cached version of your site. Still don't see it? Please send an email to help@purechat.com, so we can help you.