Apps

Anti-Malware

a.k.a. Anti-Virus, Anti-Spyware, Anti-Adware, etc.

SEE UPDATES
Windows Defender is built into Windows 10 and provides Malware protection by default; just run your UPDATES
Most devices include Anti-Malware protection as part of their UPDATES
It is generally more important to UPDATE than to add additional layers of protection.
Multiple Anti-Malware software that is designed to work alone may even conflict and attempt to detect and remove each other!

Sophos Home Free for macOS

Backups

Backblaze - The 3-2-1 Backup Strategy
A 3-2-1 strategy means having at least 3 total copies of your data, 2 of which are local but on different mediums (read: devices), and at least 1 copy offsite.

2 of which are local but on different mediums:

at least 1 copy offsite:

Other Backups

Make sure these backups are either in your 3-2-1 Backup Strategy or an equal/better solution.

CryptoParties

Devices

Password Managers

Resources

Secure Messaging

How to: Avoid Phishing Attacks
How to Choose the Right Messenger

Why You Should Stop Using Telegram Right Now
Why I told my friends to stop using WhatsApp and Telegram

Cutting the Wire
Messaging app Wire confirms $8.2M raise, responds to privacy concerns after moving holding company to the US

Secure File Storage / Sharing

Security Plan (Threat Modeling)

Services

Paid:

Two-Factor

Updates

Remember to run a BACKUP before Updates to avoid potential data loss!

UEFI / BIOS / Firmware Updates

Apple, Microsoft Surface, and Google Chromebooks perform these updates through their built-in regular update applications.
Note that you may need to check with the vendor of any custom/specific devices (SuperMicro, system76, Purism, PINE64, etc.)

If a device or program have become Unsupported / End of Life / Obsolete you should fully upgrade/replace ASAP.

VPN

Web Browsing

How to: Avoid Phishing Attacks

Web Browser Extensions / Add-ons

Web Browsing: Anonymous