Okay, I've been through all the documentation on this website and it still does not specify what devices the Mobile Joomla module supports.

It only lists iPhone and Android, but does it support Blackberry, Symbian, Opera Mini and lower budget phones?

Thanks,
Chris

It support all kinds of devices, from ancient WML-based browsers to modern ones. All devices are split into 5 groups:
1. WAP (for ancient WML-based browsers)
2. i-mode (for some old Japanese phones)
3. Smartphones (all devices with HTML support, including Android, WP, BB, Symbian, OperaMini, etc)
4. iPhone (separate group because of some websites use iPhone-specific thing like "Add to homepage" popup, etc)
5. Tablets (in MJPro)

Excellent! Thanks Dryabov! Will be purchasing the "Pro" version and flat template soon.

I have been looking at Mobile Joomla recently and am fairly happy that it works on my Android phone. I have been informed by one of my clients that that it does not function on their iPhone.

I have also tried it on an Android Tablet (Nexus 7) and iPad. On the iPad it is not a problem as the sites show OK in landscape anyway but the display on the Nexus is all over the place.

At the moment I am looking at the Basic Version to see what it is capable of. I see that you list iPad support in the Pro version, is this also the case for iPhone and Nexus?

Like a lot of things it is impossible to have all devices available for test purposes.

iPhone is supported by MJ Community/Basic (so I don't how to make it nonfunctional on iPhones). MJ Pro support tables by adding "Tablet" tab that is similar to Smartphone and iPhone ones, so that you can set mobile template for tablets as well.

Well it certainly does not work on the iPhones that I have reviewed it on. It is very similar to the display that I have on my HTC Android prior to installing the basic version. The site I am having problems with is www.wycombehypnotherapy.co.uk/

I have added two images , both screen prints one from iPhone and the other from Android.

MobileJoomla includes several "demo" templates, and after installation it set mobile_iphone template for iPhone devices and mobile_smartphone for smartphones (Androids, WPs, BBs, etc.). That's why there is difference in your screenshots. If you like to have single template for all mobile devices, set it in "Template" field of MJ settings page.