The app, First Responder Covid-19 Guide, uses Apple's ResearchKit and CareKit software as well as up-to-date information from Stanford experts.
The goal is to ensure that first responders can "efficiently access needed medical care while working under the safest possible conditions" as they battle the coronavirus pandemic.
"Our researchers were among the first in the nation to develop and deploy our own Covid-19 test, a rapid response that has equipped Stanford Medicine with a crucial tool for protective and caring for patients during this pandemic," said Robert Harrington, a physician who is Stanford's chair of medicine, in a statement.
"We are pleased to have the support from Apple to further bolster our shared community by offering testing and a new app."
Stanford also said it had begun to offer priority drive-through coronavirus testing to police, firefighters and paramedics in the Santa Clara and San Mateo areas of Northern California.
"Our outpatient testing has connected thousands of patients in our community with the medical care they need, while also helping to contain this dangerous pandemic," said , Megan Mahoney, a physician who is Stanford's chief of general primary care.
"By extending high-priority testing to our local first responders, we're ensuring that this important population knows they have our unwavering support."