There are a variety of self-management apps that can support the advice you give - all are in the files and links section below.
All Sorts - The Ministry of Health, in partnership with the Mental Health Foundation, has launched All Sorts, a multi-media mental wellbeing campaign to support New Zealanders through the challenges of the latest wave of COVID-19 infections.
Melon Health #ArohanuiNZ for self-care and support during COVID-19 - This has moderated chat, resources by category and journaling. It is currently free (but may not remain free).
Just a Thought: Staying on Track has also launched a way to stay on track during COVID-19. It introduces easy-to-use, practical strategies to cope with the stress and disruption of day-to-day life as an impact of COVID-19, teaching participants how to support their mental and emotional health through learning how to look after their worry and choose behaviours that will help them and their whānau stay on track. Just a Thought also offers depression and anxiety modules.
depression.org.nz - The Journal is an free online CBT resource designed mainly for people experiencing mild to moderate depression or anxiety.
Getting Through Together is a website specific to COVID-19 response with links for financial/social support as well as other general advice.
Headspace is a specific mindfulness app which is currently offering some content for free during COVID-19. It includes meditations, sleep and movement exercises.