Summary of the assay for an App

We publish a summary of an App’s assay on the top-level questions as follows:

  • Impact on the pandemic.
  • Avoidance of downsides or risks.

These are separately rated.

Symbols explained

For both ratings, the same symbols are used.

  • Independent assessment by third parties, such as App Assay or other independent organizations or individuals, without enough help from the App Creators to qualify as an Audit, is shown in the bottom-left corner. The color of the arc can be red, yellow, green, or gray, dependent on the third party/parties' external assessment (see below).
  • If an App has been audited, a single colored circle is used for the rating. The color of the circle can be red, yellow or green, dependent on the result of the Audit (see below).


  • The App is implementing world-wide best practices on this subject, or is close to them. We have not found major concerns.
  • The App implements a set of tradeoffs on this subject that are debatable. Reasonable people may disagree on them. For example, is it better to take an extra month of development time for an App that makes a significant positive impact on COVID-19, if during that time much better privacy protections can be implemented?
  • At App Assay, we do not make tradeoffs like this; we only provide the information to enable others to make this tradeoff.
  • Insufficient information is available to ascertain whether the App is effective, or what risks and harms may exist when using the App.

Hypothetical example

For example, a hypothetical App may have the following summary:

Impact on the pandemic

  • While the App traces contacts, it encourages large crowds to congregate for prolonged periods of time. As a result, its net-impact on COVID-19 is likely to be negative.

which should be interpreted as:

  • In the view of the App Creators, the App has a significantly positive impact on fighting back the pandemic (green arc upper-left),
  • while a 3rd-party assessment disagrees (red arc lower-left), with an explanation that is given in text to the right.

Avoidance of downsides or risks

  • Privacy is substantially below best practices

which should be interpreted as:

  • An audit on potential risks and harms was conducted, which found a substandard result (full circle in yellow), with an explanation that is given in text to the right.