Wrist Pipe does not collect any information about you, it's really that simple.
Beyond the information Apple provides to developers (provided you opt-in), Wrist Pipe uses no third-party analytics frameworks. Wrist Pipe does not log personal information about how you interact with it. In TestFlight beta builds, Wrist Pipe may log crash reports to your device that you can explicitly choose to share (it will not leave your device otherwise). These reports do not contain any identifiable information. Simply put, your data is your data, and it will not be shared in any form to any third-parties.