WhatsApp is still one of the most popular alternative messaging apps, and now it's getting a little better. The company is rolling out a feature that allows document sharing, starting with PDFs. As Android Police uncovered, the new document sharing feature is rolling out via what seems to be a server-side switch. This means it won't come from an app update. Once it goes live for you, sharing an attachment will offer a new Document function. You can attach a PDF to a conversation (no word yet on other file types), and even view it in your media history page for that conversation later on.