Sky Go Extra is an extension of the existing Sky Go app and brings premium content to your mobile as well as allowing you to download movies and television programmes to a laptop, tablet or mobile phone for viewing offline.
We've given the iPad and iPhone versions a good going over, which offer similar functionality to the Android app.
Sky Go has proven to be a popular choice for the company's subscribers, allowing them to stream the content they subscribe to when they they have a Wi-Fi or 3G connection.
The Extra app, as the name suggests, extends that functionality into offline usability, meaning that you can load your device up with movies and TV content. This offline availability - which remains for up 30 days from download or 48 hours from when you hit play - is a key addition, but it does come at a monthly price of £5.
It's also worth bearing in mind that this £5 still only allows you to download the content that you subscribe to with Sky - so if you don't have the movies package on your Sky TV deal then you won't have access on Sky Go Extra through either streaming or download.
That £5 fee for downloads is likely to be the major sticking point for many people - especially if you are already paying for the content as part of a hefty TV package. But an upside for those who do decide to shell out the extra fee is that they can up the number of devices linked to their Sky account from two to four.
The main competitors to this kind of subscription content deal are Lovefilm (owned by Amazon) and Netflix - but both of these services offer streaming, like the original Sky Go service, and not the ability to cache content for offline viewing.
Onto the experience; for those with the Sky Go app then it is merely an update to that - the logo is the same and the 'Extra' bit is really only obvious when you are in the app.
When you first open it, chances are you will not have signed up for the extra services so you will see splash screens encouraging you to do so. You will see the two key additions - a download tab in the main navigation and, when you are looking at content in the on demand section, the presence of a download button on most of the content.
If you happen to click this without having a Sky Go Extra account you will be given a brief message explaining that this isn't for the likes of you, and that you need to go and set up the additional service on your account. You can do this through the website or on the phone and, let's face it, it isn't the most elegant part of the experience.
That pain point out of the way, when you have signed up (and rebooted the app) you can now use the shiny new buttons to your heart's content.
The service itself is incredibly easy to use, and will be familiar to anyone who uses the BBC iPlayer download system.
You can browse through to the content that you want - be it film or television - and then when you see the download button on the description, just click and set it going. One minor niggle is that you don't get told how your download is progressing from the content itself - for that you need to go the downloads tab - but if you have already downloaded the content then the download option is greyed out and changes to 'downloaded'.
If you have active downloads running then the downloads tab will have a pulsing icon, and when you go through you will be able to see what you are downloading (and how the download is progressing), what is queued to download and what you have already downloaded.
An edit button will allow you to delete the content you no longer want or want to download. It will also allow you to pause or resume the download, start playback and also displays how long you have to watch the content.
For content you have started watching this will be a portion of 48 hours, for most non-watched movies then you have 30 days (which will show as 29). Catch up TV shows wil often only have seven days to view after the date of broadcast and some movies will have limited time if they are about to go off of Sky's service. This is annoying, but down to licensing restrictions.
You can only download one thing at a time, which is a little frustrating but to be expected - and downloads pause when you are not in the app, which means that you can't just get on with something else on your tablet.
The phone experience is very similar - the downloads tab drags down from the top of the app and the screens are optimised for phone.
Obviously you also keep all the Sky Go functionality you had before - allowing you to stream movies, TV and sports either live or on demand.
Neither streaming nor downloads are availble in HD - which is a bit of shame - with file sizes obviously dependent on the length of the content.
Our biggest movie download so far was Gangs of New York which weighed in at well over 1GB.
There is no limit set on the amount you download beyond the amount of storage you have - and you can store to an SD card on Android although it will only play back on the device you downloaded it to.
One of Sky's big selling points will be the 'freshness' of its content. It is billing Sky Go Extra as the UK's first service to offer downloadable Hollywood movies as part of a subscription, and with many major series on catch-up, its own drama and comedy offerings and 'box sets' of some iconic series, the impressive movie offering is not the only string to its content bow.
WIth the likes of Lovefilm and Netflix you are unlikely to get the last burst of major movies - with both choosing big old libraries of old titles over expensive new blockbusters.
That could well work in Sky's favour; its existing relationship with studios has helped bring it to a place where studios are okay with the download system and the opening salvo of available titles at launch is already impressive.
The likes of The Grey, Tron Legacy, Sherlock Holmes: A Game of Shadows, Hanna and Cleanskin were all there for our download pleasure, along with older gems like Rambo: First Blood Part II.
There were some surprising gaps, however, although it remains to be seen if they are ironed out. Anchorman was available to stream but not download, and many of the Sky commissioned and owned series like Mad Dogs were also not available for the Extra service.
There will be plenty of grumbling about the amount of money that it costs to get Sky Go Extra - especially given that there is a bolt-on fee on top of the subscription people already pay - but there's no denying that this is a well designed, incredibly well stocked service.
For those people who already have Sky Go and the movies subscription, the extra £5 buys a service that will be incredibly useful for anyone that travels, has patchy service or just wants to have more freedom in when they can watch some spectacular content.
Aside from the cost the service is not perfect - the sign up is clumsy, there is no HD option and some content is mysteriously unavailable at the moment - but this is nitpicking at a service which provides something we simply haven't seen enough of.
This unlocks premium content like movies in a way that is incredibly powerful - not being constrained by the pesky streaming woes of otherwise superb services like Lovefilm, Netflix - and, of course original Sky Go means that, for a significant cost, you are masters of your own viewing.
The movies are fresh and new, the TV catch-up is great for commuting and the whole service is an ideal solution for those that are time poor and connection light. £5 is not a hefty price to pay - but it is an annoyance for many and will be a major talking point for Sky Go Extra.
And that's a shame, because it is otherwise pretty much exactly what people have been demanding for their shiny tablets and phones for years; and the service itself is lovely.