Uptake of electronic cigarettes (EC) has escalated in recent years. While some regard EC as a game-changing innovation that will radically increase smoking cessation, others believe EC allow smokers to manage smokefree restrictions, promote dual use, and put at risk decades of tobacco control achievements. Smart EC allow usage data to be collected passively and provide unprecedented insights into how EC use evolves. Using a smart EC and active collection of smoked tobacco use via a smartphone app, we will examine whether dual use is a transitional or sustained behaviour that supports continued smoking. This feasibility study tests the acceptability of the smart e-cigarette among EC users of differing devices, and explores compliance with an app-based ecological momentary assessment collecting smoked tobacco use data over a two month period. The full study examines whether EC support smoking cessation and tests their potential to help achieve New Zealand’s smokefree 2025 goal.