Thanks for your clarification. MacOS might solve your need for making screenshots look presentable but there are still many situations where it doesn't solve the problem (e.g. only showing a small section of a page instead of the full window, people using Windows/Ubuntu or mobile devices). That's what I am aiming to solve with Screely.

I also want to add many more features to Screely that MacOS can't do such as gradient backgrounds, custom image backgrounds with company logo, tweet this image and much more.