The app was created in 2020 in response to the COVID-19 pandemic, in a collaboration between Zoe, King's College London, Guy's and St Thomas' Hospitals with funding granted by the UK government until April 2022.

[1] The purpose of the app was to track COVID-19 symptoms and other salient data in a large number of people, to enable epidemiological results to be calculated.

In the early months of 2020 he used his startup company ZOE Global Limited to build a Covid Symptom Tracker app in collaboration with King's College London and Guy's and St Thomas' hospitals.

[5] At the end of April 2020, the project received assistance from the Department of Health and Social Care which allowed it to offer up to 10,000 COVID-19 tests each week to participants.

[17] Users give personal information including age, gender and location, and report if they have any underlying chronic conditions.

[16] Using data from the app, researchers were able to identify six distinct types of COVID-19 and forecast which initial symptoms were more likely to lead to severe illnesses.

[24][25] Zoe Limited also provides in the US and UK, as a separate product, a "personalized nutrition program" whereby the company supplies sensors to quantify a person's gut microbiome, blood fat, and blood sugar responses to food intake, alongside an app which uses this data to recommend dietary modifications.