Paint.net and the Scratch paint editor.
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Paint and GIMP.
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Gimp.
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I have now mastered Sumo Paint, since it's basically an online, free version of Photoshop.
I use PS occasionally, but that requires me to connect to my school-college network, and I really can't be darned to go through all that when I can simply go to the Sumo website and open it up with no hastle.
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