Add the option to persist a sidebar with thumbnail previews of the entire document for quicker skimming and bookmarking. Similar to what Preview on Mac has, as well as Notability 5 for iPad. This makes it easier to quickly go through a document to find a specific page, and bookmark specific pages. The current process for finding a specific page opens up an overlay that covers the entire screen and removes me from my current context, which is really cumbersome.