Marissa Mayer, the former Yahoo CEO and early Google employee, has joined a wave of new entrepreneurs seeking to reinvent basic software tools aimed at making people more productive. 

Ms. Mayer’s new startup, Lumi Labs, is building a suite of such “productivity” apps, starting with software for managing contacts, which is in early testing, said two people familiar with her plans. The apps Lumi plans to launch are broadly-connected to the mission of helping people make introductions to others and schedule events, one of the people said.

Lumi’s product plans, which haven’t been previously reported, are the latest sign of a resurgence in startups, including the email provider Superhuman and collaboration toolmaker Notion Labs, that see opportunities for innovation in the productivity market.