Acknowledgements

The authors would like to express their heartfelt thanks to the following for their contribution, time and efforts in ensuring the success of this project:

• The participants of the study and all those supporting their involvement.
• The recruitment partner (Nativve) for their efficient, professional and effective management of recruitment advertising.
• The Norwich Clinical Trials Unit for their management and support for trial delivery.
• NHS Norfolk and Waveney Integrated Care Board.
• Darren Leader Studio Ltd for designing the Quit Sense logo.

Author contributions

Felix Naughton (https://orcid.org/0000-0001-9790-2796) (Professor of Health Psychology) conceived the study project and obtained project funding, led on app design, led on protocol development and led on drafting the report.

Aimie Hope (https://orcid.org/0000-0002-1920-0876) (Senior Research Associate) led on protocol development, contributed to app design, led on data collection, led on the process evaluation and contributed to drafting the report.

Chloë Siegele-Brown (https://orcid.org/0000-0002-9229-3351) (Academic Clinical Fellow in Public Health) led on app development and contributed to drafting the report.

Kelly Grant (https://orcid.org/0000-0001-5319-8127) (CTU Trial Statistician) led on the statistical analysis and contributed to drafting the report.

Caitlin Notley (https://orcid.org/0000-0003-0876-3304) (Professor of Addiction Sciences) helped conceive the study project and obtain project funding, contributed to the qualitative process evaluation and contributed to drafting the report.

Antony Colles (https://orcid.org/0000-0002-2268-0903) (Senior Data Programmer) developed the study database and landing website and contributed to drafting the report.

Claire West (https://orcid.org/0000-0001-7649-9600) (Senior Data Programmer) developed the study database and landing website and contributed to drafting the report.

Cecilia Mascolo (https://orcid.org/0000-0001-9614-4380) (Professor of Mobile Systems) helped conceive the study project and obtain project funding, contributed to app design and contributed to drafting the report.

Tim Coleman (https://orcid.org/0000-0002-7303-4805) (Professor of Primary Care) helped conceive the study project and obtain project funding and contributed to drafting the report.

Garry Barton (https://orcid.org/0000-0001-9040-011X) (Professor of Health Economics) helped conceive the study project and obtain project funding, led on the health economics and contributed to drafting the report.

Lee Shepstone (Professor of Medical Statistics) led on the statistical analysis and contributed to drafting the report.

Toby Prevost (https://orcid.org/0000-0003-1723-0796) (Nightingale-Saunders Chair of Complex Clinical Trials and Statistics) helped conceive the study project and obtain project funding and contributed to drafting the report.

Stephen Sutton (https://orcid.org/0000-0003-1610-0404) (Professor of Behavioural Science) helped conceive the study project and obtain project funding and contributed to drafting the report.

David Crane (https://orcid.org/0000-0002-9755-0214) (Chief Executive Officer of Smoke Free) helped conceive the study project and obtain project funding and contributed to drafting the report.

Felix Greaves (https://orcid.org/0000-0001-9393-3122) (Clinical Senior Lecturer) helped conceive the study project and obtain project funding and contributed to drafting the report.

Juliet High (https://orcid.org/0000-0003-2555-2349) (Senior Trials Manager) contributed to regulatory and Clinical Trials Unit related content and contributed to drafting the report.

Disclosure of interests

Full disclosure of interests: Completed ICMJE forms for all authors, including all related interests, are available in the toolkit on the NIHR Journals Library report publication page at https://doi.org/10.3310/KQYT5412.

Primary conflicts of interest: David Crane is the Chief Executive Officer of Smoke Free, a smoking cessation app unrelated to this project, and owner of 23 Ltd. Garry Barton is a member of an NIHR-funded Clinical Trials Unit and receives income via employment by UEA. Toby Prevost has been a member of an NIHR Public Health Research Funding Board and NIHR Covid-19 Reviewing Committee. Felix Greaves has been a member of an NIHR Public Health Research Funding Board, NIHR Public Health Research Prioritisation Group and NIHR Public Health Research Programme Advisory Board. Felix Greaves is also employed by NICE. None of the other authors have competing interests to declare.

Data-sharing statement

All requests for data should be submitted to the corresponding author for consideration. Access to anonymised data, excluding location data, may be granted following review.

Ethical approval

Ethical approval was received from the Wales REC7 NHS Research Ethics Committee (reference 19/WA/0361) on 28 January 2020.

Department of Health and Social Care disclaimer

This publication presents independent research commissioned by the National Institute for Health and Care Research (NIHR). The views and opinions expressed by the interviewees in this publication are those of the interviewees and do not necessarily reflect those of the authors, those of the NHS, the NIHR, MRC, NIHR Coordinating Centre, the PHR programme or the Department of Health and Social Care.

This monograph was published based on current knowledge at the time and date of publication. NIHR is committed to being inclusive and will continually monitor best practice and guidance in relation to terminology and language to ensure that we remain relevant to our stakeholders.

Disclaimers

This manuscript presents independent research funded by the National Institute for Health and Care Research (NIHR). The views and opinions expressed by authors in this publication are those of the authors and do not necessarily reflect those of the NHS, the NIHR, the PHR programme or the Department of Health and Social Care. If there are verbatim quotations included in this publication the views and opinions expressed by the interviewees are those of the interviewees and do not necessarily reflect those of the authors, those of the NHS, the NIHR, the PHR programme or the Department of Health and Social Care.