New York City-based smart ring developer Ringly raised $5.1 million in a round led by Andreessen Horowitz with participation from High Line Venture Partners, Silas Capital, and PCH. Existing investors include First Round Capital, Mesa+, Social+Capital Partnership, and Brooklyn Bridge Ventures.

The company has created gold-plated rings that connect to the wearer's smartphone and alerts them about incoming calls, texts, emails, and app notifications by vibrating. Ringly connects to its companion app via Bluetooth. From the app, users can set up the types of alerts they'd like the wearable to notify them about. Users can also customize the type of vibration or alert they receive from the ring to distinguish different kinds of alerts. Some of the apps that Ringly can sync alerts from include Uber, Facebook, Pinterest, and the phone's native calendar app.

Understandably, the startup began with integrations with some of the most popular apps. 

Although Ringly has not added any health and fitness features to the device, there are many clear use cases for this form factor for healthy behavior change and health-related reminders. It's likely that some health apps will work with Ringly.

But, Ringly also said that it plans to add more functionality to the ring in the future.

In the "looking ahead" section of the company's frequently asked questions, the company includes a question about whether the the device will offer more features later on, and one feature they listed in the question was sleep tracking.

And as a response, the company said: "Ringly is focused on designing beautiful pieces that seamlessly integrate into our lives. We are adding functionality every day, but at launch the ring will provide notifications and alerts. Keep an eye out as we announce additional functions in the coming months."