My essentials in a strictly manual sense are as follows:
- a good note taking app, whatever works best for you
- a timer app like Pomodoro, it will keep you sane if you work at home
- Insomnia as a REST client for API testing
- Charles proxy, for mobile testing when you need to know what is going on in the API
- mobile device simulators if you can’t afford extra phones
- Slack/Discord, because even if your work doesn’t use it, you need it for tool communities
- a good bookmarking strategy, be it in browser, app, or in notes
- a good list of books to read: Atomic Habits, Clean Code, Agile testing, etc
- a good head on your shoulders to make good decisions with a keen eye
- your own natural curiosity about the world