HeartMath Avis 

I would not recommend this product. I bought the professional version which was over $500. When the sensors stopped working I emailed and got non customised responses, multiple times. I asked to speak on the phone as email responses were so poor. I am in Australia and they said this was not an option, I don't even know if they knew I was in Australia. Pretty average for a tech company and they didn't give a reason for this. I bought a new sensor to see if that would work and it didn't. Took ages to get a refund for that. It's also based on pseudoscience. I bought the Polar10 which has more accurate features and it's only $100.

Thought I would write a review just to help anyone condidering purchasing. I hesitated for years and finally bought when feeling desperate to help health wise. At fist few trys I thought this is crap!! Makes no difference if I do a/b/c. Stuck with it. Tend to do it in the morning whilst reading and it has helped me cultivate more calmness and this contributes to a better way of being in the busy day. For me well worth the money for the benefits.

I've had this device for over a year to help with stress from bereavement & my cancer diagnosis. As a result of the last 2 years my head has been ringing non stop & this device most definitely for me has lowered the tinnitus after using & helped me to find a calmer state of mind. I find that a 10min session twice a day in a quiet space with the device gives me a positive state of mind to tackle my situation.

Total waste of money. This caused me so much stress I absolutely hate it.
I had the older one which was ok but the battery died and you can’t just replace the battery (so much for environmentally friendly because that wouldn’t make the company any more money) so I had to buy a new HeartMath All the company wants to do is sell you something more.

It’s difficult to figure out how to use, “Customer service” tells you to read the directions - if they were decent I wouldn’t be calling them. Turns out there are two HeartMath apps (by the same company) and I had the wrong one. Why two?? I still can’t figure out how to use it - all I want is my breathing timed. It shouldn’t be so hard. So now I’m going to do what everyone should do; relax, breathe, pray and think good thoughts. And it’s Free! No need to waste your money on this piece of junk.

Beware. I had to get permission to delete my account. Granted, my information wasn't top secret with thus company, but something is wrong for an app like this to require I ask to delete my account. And then I had to badger them to actually delete my account.
I am an experienced coherent breathing practitioner. I can tell you that this app does nothing more than spit out a number based on how well you follow the mandala.
That's not coherence.
Stay away. Get a live teacher to show you how to breathe for your mind and body. There are many techniques. Heart Math is not one

If you're considering purchasing anything from this organization, I'd recommend you give their research library a close look. It substantially consists of non-peer review articles and articles published in predatory open access journals.

They believe the benefits of their techniques are due to the unification of the heart with a global consciousness that transcends the bounds of space and time. They believe the heart is capable of receiving messages from the future via the earths magnetic field. They believe the heart is capable of telepathy, psychokinesis, and precognition. Most of their techniques are meant to amplify these alleged psychic powers, even though they obfuscate this behind coded terminology like "coherence", "synchronization", "non-local intuition", etc.

They repeatedly emphasize that their techniques are science based. I don't think that means what they think it means.

Good for research projects needing HRV (heart rate variability) data. Used for my dissertation.

The HeartMath InnerBalance proved to me that heart coherence is real and how I can best be in a state of heart coherence.