LiquidText is another excellent app for reading and annotating PDF documents. With the app, your Apple Pencil and iPad Pro, you can draw, freehand-style, on documents imported from Box, Dropbox, Google Drive, iCloud Drive, or a website page you’ve imported. You can also import Word, PowerPoint, and PDF files. Imported docs have a workspace on the right. You can highlight sections of a document and then drag/drop those excerpts into the workspace, to call attention to them. You can group objects in the workspace, too, according to your needs. The app is free, but you’ll need to upgrade to LiquidText Pro ($20) for the digital inking.