Will the app be free once you buy cards? Vessel Health August 26, 2020 06:09 Updated Yes, the app is free to use. All you pay for is the cards. Related articles I can buy test strips on Amazon, 100ct for $9.89. What makes these better? What is the shelf life of the test strips? How can you accurately detect vitamin levels through urine? Isn't my hydration always going to be low if I'm testing first thing in the morning? How are the results given? Actual numbers or just a ‘wellness score’?