Turns out the Apple Watch’s motion sensors can be a useful tool for Parkinson’s patients and their physicians. The FDA has granted approval to Rune Labs to use their software paired with the Apple Watch to track symptoms of Parkinson’s disease, Reuters reported today. The San Francisco-based digital health startup has created software for watchOS that can detect common Parkinson’s symptoms such as tremors, involuntary or slow movement, rigidity and poor balance. Smartphone and other remote forms of monitoring Parkinson’s have been around for a while, but this is the first software designed for the Apple Watch that the FDA has cleared for motion disorders.

Since the Apple Watch Series 4 was first released in 2018, the wearable has been able to detect hard falls and offer advanced activity metrics. The company that same year added a Movement Disorder API to its open-source ResearchKit, opening the door for developers to create watchOS apps to track Parkinson’s and other diseases. As Rune Lab notes, the company is the first to make use of the API for commercial purposes.

The watchOS app by Rune Labs will give physicians access to patient movement data over time, which can further supplement the information they get from an in-person physical exam. Rune Labs also notes the Apple Watch’s tools aren’t capable of giving patients a complete picture of their disorder. “Of course, there are limitations to Apple’s Movement Disorder kit: tremor and dyskinesia are only two symptoms in Parkinson’s Disease, and the classifiers themselves are not yet perfect,” wrote Rune Labs founder Brian Pepin last year in a blog post.

Apple has focused a lot of time and money on expanding and updating the Watch’s health and fitness tracking capabilities, with many more to come in future updates. Earlier this month the FDA also cleared watchOS’s AFib History feature — which monitors irregular and extremely rapid heartbeat — and will be released in the upcoming watchOS 9 update.