One of the very first apps I bought for my long-gone iPad 1 was the outstanding GoodReader. I paid $4.99 for it when I thought it was nothing but a semi-decent PDF reader because the iPad was woefully lacking in that regard. As time has gone on, what was once a one-trick-pony has turned into a complete toolkit of things I didn’t know I needed.

What can it do? What can’t it do? I use it to pull files down from Dropbox. You can use it to pull down files from the cloud storage service of your choice. It plays well with Google Drive, SkyDrive, your own FTP server, your network-attached storage, you name it. Any regular IOS user knows how finicky Apple is about letting you download things directly to an iDevice. GoodReader helps get around that by opening almost anything you throw at it via GoodReader itself. When it does that, it then doesn’t matter where the iPad decided to actually stash the thing – it’s just right there to read. GoodReader also gives you the option to sync your documents with your cloud storage, ensuring that if you make changes on the iPad, they’ll show up back at your computer.

Over time, GoodReader has expanded to support opening video within the program and to behave as Instapaper (or Pocket, or Read it Later, or the offline reading app of your choice) does and save your material offline for later reading. If you’re not already using an offline reader app, you really should be. If nothing else, stacking up articles to read comes in unbelievably handy when enduring long CLE presentations.

All of the above features have simply been value-added bonuses in terms of my own use. What I originally got it for, and what it continues to be great at, is (1) being able to process huge – as in 20MB+ – PDFs and (2) being able to annotate PDFs huge and small. I had roughly 900 pages from an administrative record grouped into 6 large (and extremely unorganized) PDF files. GoodReader allowed me to navigate through those documents with ease and mark up everything as I went.

The good folks over at recently reviewed another PDF program, iAnnotate, that seems to have a much richer feature set in terms of how it can annotate. If all you’re looking to do on the go is mark up documents, that might be a better choice. However, iAnnotate doesn’t take the Swiss Army knife approach that GoodReader does. For me, GoodReader performs the functions of a number of apps (downloading from/uploading to the cloud, syncing document versions, offline reading, annotation) and does it seamlessly so that I need never leave the app. Probably the best $5 I have ever spent at the app store.