You can be skeptical and you don't have to buy our solution, but hopefully we can agree that tapping a chip is a superior solution.
It may sound harsh to you that fellow users here are questioning your business without testing it but it's normal for every new business. Especially one that has to do with sensitive users informations.
The users above are right. You should add more informations about your service so people can have more trust.
According to Google play your app review is 1.0 with 1k downloads. This only can put new users off.
From your Google play review, it seems you have fixed the errors as per the comments below the reviews, but there is no positive review(s) that support the changes.
I suggest you should have few people test run your service, if things are fixed and right, their positive review can boost your Google ranking, and eliminate skeptical minds.
When a service is good, it markets itself.