The goal of this clinical trial is to understand how the introduction of an app-based intervention changes knowledge, attitudes, and practices on COVID-19 self-testing.

Rapid diagnostic testing has been shown to be an important tool in controlling the spread of the COVID-19 pandemic by identifying people when they are likely to be most contagious and reducing crowding at testing sites. In addition to employer-mandated testing, rapid antigen tests are becoming increasingly used by individuals. A method to promote frequent self-testing would help break the chain of viral transmission, slow the spread of disease, slow the spread of vaccine-resistant variants, and improve pandemic management.

The ubiquity of smartphones along with their data connectivity capabilities and onboard sensors make them an attractive tool to complement rapid diagnostic tests and an important component of decentralized testing. Smartphone-based tools have shown high acceptability among healthcare workers for the real-time tracking of rapid test results.

Inclusion Criteria:

• English-speaking
• 18 years old or older
• Owns a smartphone running either Android or iOS operating systems
• Willing to download a COVID-19 self-testing app
• Willing to receive and send text messages for the study (and fill out surveys linked from text messages)

Exclusion Criteria:

• Not willing to self-test themselves with COVID-19 rapid tests

There is no plan to make individual participant data (IPD) available to other researchers. However if plans change and IPD is made available to other researchers, the data will be de-identified unless disclosure of the information is required by law or the participant has authorized the disclosure.

Data that may be shared (not individual participant data) would consist of responses to the baseline and follow-up questionnaires, and recorded self-testing frequency. If the participant is in the intervention (App) group of the study, this may also include scans of the self-tests taken through the app, user engagement metrics tracked by the app, and responses to app feedback questionnaire(s). To reiterate, this data would be de-identified and would not be able to be traced back to the participant.