This is a Form icon. We've made it in iOS style, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 12,500 icons, all in the same style and quality.
This looks like a square with several objects in the center of it. At the top of the square, there is a line on the left and a horizontal rectangle on the right. These two same shapes are across the middle. at the bottom, there's a small square and a line to its right.