Some of the digital tools and apps that I find useful, see also my /uses page for an even more extensive list.
Password Manager
LastPass and OnePassword examples. They're worth paying for, and save you a lot of time once you put in the initial effort to get them set up with the browser extensions, a desktop app, and on your mobile device(s). If you share passwords a lot (with a partner or creative collaborator) this makes things a lot easier too, you can have a shared folder of login credentials, or share logins one at a time.
Google Suite
I use google docs and sheets a lot -- just handy for organizing things and doing math. Amy and I use them extensively for All Well, and we wrote a blog about how we write sewing pattern instructions booklets with them. The collaborative aspect is most useful.
Airtable
A bit fancier than Google sheets, I use this for tracking Goals, Projects, and Tasks, and having one trusted system to keep track of them all. (This is somewhat GTD style, I also use a bullet journal with this.) It's nice to be able to set up trackers that are specific to the projects, like sewing and sewing patterns, or things to buy, or things to cook. I make custom statuses for those different types of tasks, and then can see them on a kanban style board or other ways of displaying, too. (Similar to this in the past, I've used Trello, Notion, Jira, and a bunch of other project management tools, but Airtable is my go-to now.)
Craigslist and eBay
Using searches with boolean operators (like the OR pipe for Craigslist vertical pipe), exclude terms, phrase searches, groupings, and wildcards, plus setting up alerts. This helps me find obscure bindery tools or deals on other stuff I'm looking for. Here's a good how-to for CL.
Adblocker & Tracker Blocking Extensions
Google to figure out which ones you want, and put them on the browsers you use on your computer and phone. I've used Ghostery and PrivacyBadger, as well as Adblock Plus. You can also turn off third party cookies in the settings in Chrome, and try out other browsers like Brave or Duck Duck Go. To cut down on online advertising, it's also worth it to go to My Google Activity and turn OFF saving settings there -- https://myactivity.google.com/myactivity -- I have "Web & App Activity", "Location History", and "YouTube History" saving all turned off.
Lightroom Mobile
I use this (free) app a lot for editing photos.
Pranayama
A meditation app that I like! Has a breathing visualization and lets you customize the length of the in-breath, hold, out-breath, hold steps.
Peakbagger
We use this site and mobile app a lot for planning hikes and climbs.
Spectrolite
The mac app that Adam and I are making for ANEMONE, for riso printing and making zines! I use it a lot!
Zapier
Automate lots of stuff -- for example, we just made a new "zap" to send ourselves an email when the Spectrolite help + bug report google form adds a new row. That way we don't have to remember to check it manually. IFTTT is a similar service.