Microsoft discontinued the Microsoft Band over two years ago. Now, the company plans to kill off the Microsoft Health Dashboard apps and services by May 31st. All these backend services will lose support and apps will be taken out of the Microsoft Store, Google Play, and Apple's App Store. Existing Band users can export their data before the end of May. Services powered by the cloud will stop working by June. But the fitness tracker can still record daily steps, workouts, heart rate, activities, sleep, and work as an alarm. However, if you reset the device, Microsoft says it will be "impossible to set up the device again."
Some Microsoft Band owners are eligible for a refund. Active users who synced data from a Band to the Health Dashboard between December 1, 2018, and March 1, 2019, can apply for a refund on their hardware. Microsoft is offering US$79.99 refund for Band 1 owners, and $175 for Band 2 devices. If your Microsoft Band is under warranty, the same refund values will be available.
Source: Microsoft