If you’re in the .NET world, NCrunch is basically Wallaby. Saves me a huge amount of time and helps me write better tests by identifying where I’ve missed branches or setup test data incorrectly through the line indicators.

> - Jetbrains IDEs - the refactoring and debugging tools are second to none.

It might not quite be in the 100 hours bucket over the past 2 years, but it's close... using their toolbox app has made them much easier to keep installed/updated on my Linux workstation.