Beekeeper, the Switzerland and U.S.-based startup that provides a mobile-first communications platform for employers that need to communicate with blue-collar and service-oriented workers, has raised $45 million in Series B funding.

The round was co-led by Thayer Ventures and Swisscanto Invest by Zürcher Kantonalbank, with participation from previous backers including Atomico, Alpana Ventures, Edenred Capital Partners, Fyrfly, Hammer Team, investiere, HighSage Ventures, Keen Venture Partners, Samsung NEXT, Swiss Post and Swisscom.

Targeting non-desk employees, including those working in hospitality, manufacturing and retail, Beekeeper’s mobile-first platform is designed to replace more arcane communication methods, such as pen and paper and consumer messaging apps like WhatsApp.

The potential market is said to be big, too, with more than 80% of the world’s workers thought not to be at a desk and therefore arguably in need of a “Slack for non-desk employees,” which is how Beekeeper pitches itself. The company reckons 1.7 billion non-desk workers globally are either unconnected or poorly connected by a “patchwork” of consumer and enterprise applications.

Beekeeper’s clients include Hyatt Hotels, Dollar General, Domino’s Pizza, Heathrow Airport and SeaBoard Foods.

Meanwhile, with today’s Series B, Beekeeper says it plans to bridge the gap between knowledge workers and their non-desk counterparts, and further expand its offering with new features and integrations. On the product roadmap, for example, is a way for companies to be able to customise the Beekeeper experience via a “marketplace” of additional apps and integrations with systems such as Workday.