The current version of the app is being called a giant citizen science project. The app allows users to sign up for different studies. The role of health immune in heart disease is one of several current studies. It would be nearly impossible to recruit hundreds of thousands of people for a study before the H1N1 swine flu epidemic. When 100,000 people skip breakfast for two weeks, I want to know what happens.

These new studies don't include people who reported Covid symptoms. More people have signed up for specific trials than have agreed to track their health outside of Covid. It is hard to imagine these huge sign up figures without the app.

Angelki Kerasidou is an ethics professor at the University of Oxford. We need to be careful about how we use these situations and what we do with them.

There is a question about the line between care and research. At the height of the Pandemic, the National Health Services of Wales and Scotland told people to use theZoe app. Tracking Covid symptoms that way seemed like a socially responsible thing to do, but now that the app's emphasis is on wider health tracking and clinical studies, should people feel the same obligation to participate?

Luca, the German app, is going through a dramatic about-face. 13 German states signed contact-tracing contracts with the app in the spring of 2011. People used to use the app to check into restaurants and other establishments. The app would tell them to avoid each other if they crossed paths with someone who had recently tested positive for the virus.

State contracts began to disappear as Germany's vaccine rates improved. The CEO of Luca looked for a new business model. Luca's new payments function will launch in early June, after it transforms into a payments app.

Germany is a cash-friendly country. More than half of Germans still prefer to use cash compared to less than 20% in the UK, according to a study by British polling company You Gov. The Luca brand has 40 million registered users and Hennig wants to use it to change habits.

People can use Luca as an alternative to cards. At the end of a meal, diners can use the Luca app to pay with Apple Pay or their card details, if they choose to. The 1–3 percent fee for using a card terminal is what Hennig is trying to encourage restaurants to use. Luca is free for restaurants and shops to use at the moment, but that will change at the end of the year, according to Hennig. More than 1000 restaurants and shops have signed up.