If it's positive you probably have covid. If it's negative, that doesn't mean you don't have it - it needs to be corroborated by a more sensitive test. Abbott wants to use this as a screening for entering places using a phone app (meetings, etc), but it doesn't document that a person is necessarily negative. But it will weed out the positives so they can be refused entry and referred for further testing, quarantine and treatment. Also, only given emergency FDA authorization, so not a proven rigorous test.
https://www.medscape.com/viewarticle/936434
https://abbott.mediaroom.com/2020-08-26-Abbotts-Fast-5-15-Minute-Easy-to-Use-COVID-19-Antigen-Test-Receives-FDA-Emergency-Use-Authorization-Mobile-App-Displays-Test-Results-to-Help-Our-Return-to-Daily-Life-Ramping-Production-to-50-Million-Tests-a-Month