MINNEAPOLIS (AP) — Gov. Tim Walz and other Minnesota officials are urging residents to download a free app for their smartphones that will notify them if someone who’s been near them later tests positive for the coronavirus.

The app also allows them to warn others anonymously if they test positive themselves. Officials stress that participation is voluntary, and that the system contains ample privacy safeguards.

Walz also says he plans to call a special legislative session to pass a relief package that he’ll unveil Tuesday to help small businesses cope with restrictions he tightened last week to slow the spread of the virus.