Facebook is retiring three apps, blaming low user numbers.

One, an anonymous social media app aimed at teenagers called tbh, is less than one year old.

It was bought by the tech giant eight months ago after attracting millions of downloads at launch.

All user data for tbh, along with fitness tracker Moves and Hello, an app which linked Facebook information with phone contacts, will all be deleted within 90 days, the firm said.

In a statement, Facebook acknowledged that existing users of all three apps would be disappointed.

"We need to prioritise our work so we don't spread ourselves too thin. And it's only by trial and error that we'll create great social experiences for people," it said.

Facebook acquired Moves in 2014, Hello in 2015 and tbh in 2017.

Tbh ("to be honest") was downloaded 5 million times in the US in its first nine weeks, before being bought by Facebook for an undisclosed sum.

It was a platform which encouraged teens to leave anonymous positive messages for each other.

Facebook has a long track record of acquiring apps and later closing them, said Jack Kent, analyst at IHS Markit.

"Facebook's acquisition of tbh could be seen as its attempt to address challenges it was facing including trying to engage a younger, teen audience that could be less engaged with the core Facebook experience and also the negativity around the tone of wider social media conduct," he said.

"The low usage stats cited by Facebook as a reason for the closure point to the challenge of running a long-term service based on anonymous interactions, which can struggle to drive sufficient engagement beyond a niche audience."