The account was awarded without a competitive pitch; Ranieri pitched the US firm after following up on a lead from another organisation it works with.
MOOV's fitness bracelet is being branded as the 'Siri of sweat' – a reference to the iPhone voice activation software. Last year, the company raised $1m (£640,000) through a crowdfunding campaign.
Ranieri will manage all the company's UK PR activity following MOOV's launch to the UK press late last month.
Meng Li, co-founder and CEO of MOOV, said: "Ranieri's experience of working with US brands launching in the UK and its knowledge of the consumer tech industry made the agency a natural fit for MOOV. We are looking forward to working with it to make a splash in the UK market."
