It seemed pure madness that Amazon hadn't done it earlier, but finally it has launched a Prime Instant Video app for Android. Previously the company had only made the app available on its own Kindle Fire tablets, such as the Kindle Fire HDX 8.9 , and iOS devices, completely ignoring Android.

Now Android users can use the standard Amazon Android app to watch Prime Instant Video content. It's free, as you'd expect, but you do have to have a Prime account in order to access the streaming video service. The service gives subscribers a huge back catalogue of TV and film to choose from, although it's important to point out that HBO shows are only available in the US and aren't available in the UK.

It's surprising that Amazon has taken this long to support Android, as one of the reasons that Netflix is so popular is that it's available on a huge-range of devices. Amazon's restrictive policy was never going to make it very competitive. This is a further sign that the company is changing. Last week it announced that its Fire TV set-top box is coming to the UK. As well as supporting Amazon Prime Instant Video, it also carries rival service, Netflix.

While the new app should be welcomed, it seems there's a way to go before it's universally embraced. For starters, there's no Chromecast support at the moment, even though the iOS version of the app supports AirPlay for Apple TV . Reviews on the Google Play store haven't exactly been impressive, with many people complaining that the app is unreliable. "overpriced I know it is a free app. but, since it only works about 20% of the time, they should pay us... since we are beta testing their rotten, barely functional software," wrote user Shawn Hayes.

That said, the app is bound to improve with newer versions and being able to watch your subscription on more devices is a definite step in the right direction.