Pair two iPhones if you both want accountability. Either of you can approve the other's early-release request; neither can approve their own.

On your iPhone, follow the link and let TestFlight guide the install.
Tandem needs Apple's Screen Time permission to shield the distractions you select.
This is pre-release software, so bugs and rough edges are possible. Tell us what worked or got in the way.
Your distraction choices and history stay on your phone. If you pair, requests travel between the two phones through iCloud. Tandem has no developer-run server for your app data. Read the privacy policy.