This is an online text generator which can convert the text to various of text style, include Strike-through , Underline and the slash symbol. Result is not image or HTML, but plain text, which able to paste to anywhere.
It looks like a noisy signal, and overlap with previous charactor. People like to use this to decorate the text string. Text becomes hard to tell, but visible. It's very similar to invisible ink in iPhone.
iPhone/iPad, Android 4.4+ and Windows 8.1+ are native support emoji symbols. Here are 845 emoji symbols with five categories. No need to install any app or software, just click to copy and paste to anywhere you want.