You can buy a Stelo or Lingo sensor a la carte, so to speak. Each comes with their own proprietary apps, and both also partner with a wide variety of fitness trackers to let you easily track your glucose. Signos is a separate service that partners with Dexcom to use the Stelo sensors. A Signos monthly subscription includes two sensors (you have to replace the sensor every two weeks) and access to the AI-enabled weight loss management platform that offers insights, and plans, in addition to 24/7 glucose tracking.