The company has teamed up with Hong Kong-based technology firm Tink Labs to offer the Handy devices across its 650 London apartments from September.
Guests will be able to use Handy to make free local and international calls to ten countries including the USA, India and China.
Each phone will have unlimited internet access and come pre-loaded with Google Maps, Facebook, Twitter and a regularly updated London travel guide with events and special offers.
It is designed to help guests avoid costly roaming charges and service providers which don’t operate overseas.
Susan Cully, managing director of Marlin Apartments, said: “The idea of combining the functionality of a personal smartphone and concierge service into one integrated device is industry-forward.
“We are hoping for our guests to benefit from a further enhanced home-away-from-home experience.”
To protect guests’ privacy all personal data and browsing history will be automatically cleared from the devices after check-out.
Terence Kwok, founder and CEO of Tink Labs, said the partnership was a ‘testament to the importance of complete mobile connectivity in today’s tourism’.
In April the Montcalm Marble Arch became the first hotel in Europe to launch Handy.