Use Programmable Tooltip (for Mac) to save you millions of clicks
The tool: ProgrammableTooltip.com
Back in 2019, I just joined Stripe and worked on Billing Analytics. I was working the timezone part of it. Side note: daylight saving is insane. I found myself needing to convert epoch-from-millis to human-readable date extremely often when I look at the Chrome's Network tab.
Converting epoch-from-millis to human-readable date is arduous. I would need to copy the number, switch to another tab that has this site, paste the number, and sees what it is. It involves multiple clicks, key presses, and complex mouse movement. More importantly, it breaks my attention on the task at hand.
Then, it hit me. I could build an app that could read from the clipboard and show the human readable date. I was so inspired to build this. I hadn't built any Mac app before, but that didn't deter me.
It was 25 Dec 2019. My wife and I took Amtrak from Seattle to Vancouver for 3 days. The first working version was coded up during this trip. It turned out, when an inspiration hit, wonder occurred.

I didn't end up using the clipboard because I found a better and more secure way: NSService. Mac basically allows users to select a text on any app and triggers an external service to process the text. Then, NSUserUnixTask enables users to provide a script that runs outside of Sandbox and can be executed (no write nor read) by the app.
With those 2 mechanisms discovered, programmabletooltip.com was born.
The security model of this app was superb. This is where it distinctively differs from PopClip. PopClip requires the accessibility permission and doesn't run in Sandbox. It sees everything you do. This kind of apps would have a very difficult time being allowed at a large company.
Programmable Tooltip runs in Sandbox, doesn't need accessibility, and doesn't see anything you do. The selected text is given to the app by MacOS. The programmable script is provided by you and cannot be modified by the app.
Since then, at Stripe, for 4 years, I'd use Programmable Tooltip 100+ times a day. It was so convenient and slick. I'm still using to these days.
There are mainly 4 different scenarios that I find super useful:
1. Convert epoch-from-millis to human readable date

2. Open URL based on the selected text.
I can select a user ID and opens a user lookup at http://go/user/[user_id]
if I select a text that starts with user_
.
I can also open a log viewer with the selected text as the query at http://go/splunk/[selected text]
. (Stripe uses go links for shorten links!)

3. Perform code search using the selected text and offer to open VSCode, IntelliJ, or Github at specific relevant code locations.
I would highlight a part of an error stack on Github Actions and just jump to the code location on my IntelliJ. This use case is just so magical.

Other use cases that I also use or have heard: looking up the database with the selected text with a specific SQL. Calling an API to translate the text and show the translated text in the tooltip.
Since you can write your own script, the use cases are limited only by your imagination.
I also set up my 12-button mouse to trigger the tooltip with a single click. It's just so slick.
Try it out: programmabletooltip.com
I've probably saved millions of clicks so far. Wait, that's the name of the blog post!