Overall Study Name: NHS CHECK - Health & Experiences of staff working at NHS Trusts and Nightingale Hospitals.

INTERVENTION: Trade Name: Foundations App ‐ Koa Health Product Name: Foundations App Product Code: N/A Pharmaceutical Form: CONDITION: Mental Health and Wellbeing of Healthcare Staff Therapeutic area: Psychiatry and Psychology [F] ‐ Mental Disorders [F03] PRIMARY OUTCOME: Main Objective: To evaluate whether the use of Foundations mobile application impacts stress, wellbeing, anxiety, depression, functioning, resilience and sleep in a real‐world, high‐risk healthcare worker cohort. Primary end point(s): 1. The GHQ‐12 is a 12‐item scale which screens for general (non‐psychotic) psychiatric morbidity, (Goldberg et al., 1992). Secondary Objective: Not Applicable Timepoint(s) of evaluation of this end point: 4 and 8 weeks (alongside baseline) SECONDARY OUTCOME: Secondary end point(s): 2. The Brief Resilience Scale (BRS) to measure resilience is a 6‐item participant self‐report measure, which assesses an individual’s ability to bounce back or recover from stress. (Smith et al., 2008).; 3. The GAD‐7 is a well validated and widely used 7‐item measure of anxiety. A change of 4 or more on the GAD has been found to be clinically significant across anxiety disorders. (Spitzer et al., 2006). ; 4. The PHQ‐9 is the 9‐item depression module from the full PHQ. There is strong evidence for the validity of the PHQ‐9 as a brief measure of depression severity. (Kroenke et al., 2001). ; 5. The Warwick‐Edinburgh Mental Well‐being Scale (WEMWBS) is a 7‐item measure to enable the monitoring of subjective well‐being and psychological functioning compared to the general population (all items are worded positively and address aspects of positive mental health) (Tennant et al., 2007).; 6. The 5‐item Work and Social Adjustment Scale (WSAS) (Mundt et al., 2002).; 7. The 6‐item Stanford Presenteeism Scale (SPS‐6) (Koopman et al., 2002).; 8. The Minimal Insomnia Symptom Scale (MISS) is a 3‐item scale which provides a brief measure of sleeping difficulties (Broman et al., 2008).; Timepoint(s) of evaluation of this end point: 4 and 8 weeks (alongside baseline) INCLUSION CRITERIA: 1. Be aged 18 and over. 2. Be an NHS‐affiliated member of staff, working at, or with, the participating eighteen NHS CHECK sites. 3. Completed baseline survey with NHS CHECK Cohort study and have consented to be contacted for further research as part of study. 4. Be able to give informed consent to take part in research. 5. Be able to understand and communicate in English. 6. Have access to the internet to complete the surveys. 7. Have access to an email address to facilitate application registration and receive survey links. 8. Own a smartphone with access to the Apple and Google Application Stores. The following 18 NHS Trusts have been selected to include a mixture of urban and rural settings: Avon and Wiltshire Mental Health Mental Health Partnership Trust Cambridge University Hospitals NHS Foundation Trust Cambridgeshire and Peterborough NHS Foundation Trust Cornwall Partnership NHS Foundation Trust Devon Part