Advisory work shows you the same problems repeatedly. Occasionally one is worth building a product around rather than writing another recommendation about. These are the ones that got built.
Inspections that stand up when someone asks.
Captures checklists, photos and signatures in the field, works with no signal, and keeps the record intact from the first answer through to the closed corrective action.
Training logs a coach has actually verified.
Aspiring players record their training; partner coaches and academies validate the entries afterwards, so the record carries weight. Partner gyms and sports nutrition stores offer discounts when players hit targets.