Device works basically fine without app. Phone app no longer supported.
The device itself works fine, and did not require me to download the app in order to use. I had to search online to get basic instructions; they don't come with the box. It was very easy to use. The device reminds me to straighten up, whether I'm slouching forward or leaning backwards. It is comfortable to wear. The device is designed to turn itself off, and if I am still for too long it will turn off, but it is easy to turn back on so that is not a problem. Be advised that the phone app is no longer supported. But the device works without the app; you just can't use the app-supported features like personalization and step-counter.