Overlay是一款独特的Mac软件，这款软件能够为大家在桌面半透明地显示图像甚至PDF，让用户能够锁定框架并使其不受鼠标手势干扰，帮助大家更好的复制，跟踪或比较设计
A frame that allows you to have an image or even PDF displayed semi-transparently in front of everything. It enables you to copy, trace, or compare designs, images, and documents with ease since you can lock the frame and make it undisturbed by mouse gestures.
It’s a transparent overlay of an image or document on your screen that you can click through – like a transparent sticker on your screen.
Overlay is especially useful for artists, designers, and students as it allows you to make your art or design from or reference photos and screenshots.
Compatibility: OS X 10.9 or later, 64-bit processor