I'm glad to have found this thread, because I too have just received a test kit in the post from healthy.io.
I don't use phones, and R got a text a while ago from our surgery number saying I'd receive a urine test kit through the post as part of my annual diabetes review, which we assumed was an NHS test kit and a good idea because I'm not going into surgery at the moment.
Then he got a text from a different number asking him to download the app for the test results and we were both a bit dubious about this not coming from the surgery so thought we should do more research, which led me to this thread.
We will be having words with our surgery about giving out our personal details to private companies without our knowledge or consent 😡 - especially as we have specifically opted out from allowing NHS to share our details with private companies.
What do you think I should do with the test kit? I'm not paying to return it! Should I bin it, write "Unsolicited, return to sender" on it and stick it in a post box, or get R to text healthy.io to say that if they want it back they can pay a courier to collect it?