PaintCode<p>As a dev without a dedicated design department (or even when I've partnered with designers honestly) it saves me so much damn time. Get things in vector, change all of your menu icon colors in one shot.<p>Speaking of which, icons8 (<a href="http://icons8.com/free-ios-7-icons-in-vector" rel="nofollow">http://icons8.com/free-ios-7-icons-in-vector</a>) has been awesome on my current project.
Flask (awesome, I actually ditched web2py for it. Web2py is great too but it was no longer cutting it for me)
Virtualenv - for isolated python installations
i3 tiling windows manager - It actually increased my dev machine battery life with 2+ hours. This is such a big deal because steady electricity supply is a huge luxury in my neck of the woods.
Laravel Forge<p><a href="https://forge.laravel.com/" rel="nofollow">https://forge.laravel.com/</a><p>Other notables (might not be considered tools):<p>sublime, vagrant/laravel homestead, Digital Ocean, stripe, mandrill . . .
More relevant question might be what APIs or libraries are starting to look attractive of late ?<p>I would say wit.ai looks very interesting.<p>The dev stack is the same as always ~ Sublime + AWS