One of the most important questions within aging science is identifying good biomarkers of aging.
We need biomarkers that are predictive of aging rate and mortality. We have lots of biomarkers that are associated with aging rate and mortality, like cholesterol readings and epigenetic clocks. But we don't know how predictive they are.
We need these biomarkers to be more frequently measured than a full human lifespan. That way we can test interventions and see how they work. The more frequently these biomarkers can be taken (and still be predictive), the more we can make lots of personalized interventions (e.g. lifestyle, drugs, epigenetic reprogramming, gene editing).
Once we have these biomarkers, I could imagine a device like an Apple Watch giving us personalized recommendations based on population and personal data on how to slow our aging. Apple Watch captures large amounts of physiological and lifestyle data. They are increasing their data-capturing capabilities every year.
Working on biomarkers of aging is likely a very good use of time.