Doodle for Messenger - Doodle Anything and Send it on Facebook Messenger
KDAN Mobile PDF Reader - PDF Reader is the one app you can rely on when you need a portable solution to work with PDFs.
ScribbleBoard - iOS8 Keyboard for hand drawing your messages
Anvil PDF Filling API - The easiest way to programmatically populate any PDF
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request