I'm updating my review and adding a couple stars because I appreciate the Developer response and they shouldn't be faulted for Apple's horrible policies and refund review process.
Updated Review: Alerts don't happen in real time, which is what I specifically need StressWatch for. The max frequency you can get (which requires configuration from default settings of 2-5 hours) is every 15 minutes. I appreciate caring Developer responses, and if real time monitoring is not needed, StressWatch would be fine. More that watch faces don't work for all (though complications do work).
Old Review: The data was consistently several hours behind. Alerts don't come in real time (even though I made sure my settings allowed for immediate notifications). I purchased this in order to get alerts in the moment so I could make adjustments in real time. After trying it for almost a day hoping it would catch up, I canceled and requested a refund. The request was denied, I appealed, and it was denied again. Normally I wouldn't purchase without a free trial but the reviews and ratings were so high I took a chance. I think a lot of those ratings must be friends and family. I don't often write negative reviews, but this was an expensive mistake and since refunds are apparently not possible even when requested promptly because functionality doesn't work, I want to try to save someone else from a similar error in judgment.