In reply to tomthetraddad:
Back in the distant past before Tindeq existed, a clever technician built a similar device for me to do shoulder pain research.
https://www.sciencedirect.com/science/article/abs/pii/S0031940616300189
https://kclpure.kcl.ac.uk/portal/en/publications/do-postural-correction-and...
The components cost very little. I'm sure plenty of folk here could rig up something similar. Getting all the components to all work together, displaying the data clearly, and packaging everything nicely is what you're paying for.
Tindeq is currently the most developed device, the cheapest, and you are not charged a monthly fee to get the most out of your data.