From their website:
AlohaSafe Alert is a free, voluntary new service that helps slow the spread of COVID-19. It is the State of Hawaii’s official exposure notification app and has been developed in partnership with the Hawaii State Department of Health.
You control whether or not you receive notifications (you can opt-in/opt-out anytime). Notifications are only triggered if minimum thresholds of exposure are met.
The app does not track your location. It anonymously keeps track of devices you’ve been in close contact with for the past 14 days. Google and Apple cannot see your identity, nor can anyone who receives an exposure alert should you test positive for COVID-19.
Free & Simple
Anyone can download the app to their smartphone at no charge.
The app is a safe way to alert you to potential exposure to COVID-19 and help stop the spread of the virus.