Amazon has expanded use of its virtual currency beyond Kindle Fire, Digital Spy said.

Amazon Coins can now be bought or spent on the Amazon Appstore via Android smartphones and tablets for the first time.

The virtual currency was first introduced in the US last May and rolled out to the UK and Germany in November.

"Since the launch of Amazon Coins, we've been amazed by the number of customers using Coins, as well as how many Coins they're spending on apps and games," vice president Mike George said.

"Because customers can buy Coins at up to a 10% discount, they love the extra value they get when shopping in our Appstore."

Amazon claims that the introduction of Coins in the US has benefited app developers, helping them drive traffic, downloads and increased monetisation.