I don't think it's open source, but I am a huge fan of LightShot. It takes over the Print Screen key and makes it useful.
Pretty much two clicks and you can have a screenshot of anything
Hey, if you're looking for something that takes over the printscreen key, there is an awesome open source app called Katana. If you're looking for a Windows app, i would suggest Screenpresso. ( Yes I know, it isn't open source :) )
I can recommend Greenshot too - open source Windows screen grabber, though that doesn’t really do it justice. Integrated upload to imgur and other places, all that stuff.
They already have a mac version aswell! :)
Ah - somehow I'd missed that when downloading the PC version at work. Thanks, I'll go grab it now. :)
I'm pretty happy with LightShot at the moment, but I'll definitely check those out!
For Windows, I'd highly recommend ShareX. It's open source!
Just to add to the discussion: I've been using ShareX for a couple years now and I absolutely love it. It's open source, customizable, doesn't bog down my machine, can automatically upload screenshots and videos to almost any site (even Gfycat!) you can imagine, and so much more. I can't sing its praises enough.
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