I'm talking about online or web-based tools, not toolboxes. So entire development suites like Cloud9 or Visual Studio Online are off the table because they are full tool suites. These tools are simple, but continually help me out in a pinch.
Make sure to share your favourite tools in the comments below so I can learn and grow from your knowledge.
JSONLint
For the past few weeks, I've been writing and debugging a REST API client written in Java, where my POJO is being serialized into JSON and sent off in a request. I hit a few bugs where the JSON that was being generated wasn't 100% valid. This made validating it easy, and I keep it open whenever I'm dealing with any JSON that isn't continually being edited in VS Code.
Also, I missed that there was pro.jsonlint.com which provides a diff function. This would have saved me a ton of time, had I read the description provided on the main page.
Regexr
Being a JavaScript person, you'd think I'd be a pro with regular expressions. Thanks to Regexr.com I can at least appear to be. Between the reference guide on the left side, real-time match highlighting, I really like this tool and it has made learning and using regexes in my day-to-day very easy
Plus, the slick design doesn't hurt either.
Colorrrs
There are other HEX to RGB converters out there, I know. I just really like this one because it gives me a full screen preview of the colour I'm look at, and it's a pretty website.
I like pretty websites.
SmartView
Now we're getting into the protein part of our meal.
I've used Trello in the past, and generally end up ditching the project boards because I'm not a Kanban or Agile professional. Lucky for me, my fellow Western Dev Amir Barylko is a professional and has used is expertise to guide me along the path and provides me with some metrics on my throughput.
They start you off with a free account, which is where I began for a personal kanban for coordinating my side project efforts for myself. I suggest you check it out and get productive.
Full Disclosure: As mentioned above, Amir is a colleague of mine and I do support his work. That being said, I wouldn't have added it to my list if I didn't use it as much as I do, or if I found it as useful as it really is.
GitHub Explore and GitHub Gists
Last, but not least, I use GitHub Explore and GitHub Gists to explore and find code that can help guide me through solving problems, or by finding open source software and/or libraries that can help solve a problem for me.
Why re-invent the wheel when someone else has lead a team to and refined a solution to your problem already? At the very least, you can learn from their code and figure out how it applies to you're trying to do.
Thanks for playing. ~ DW