Being stuck with limited internet access most of the time, I sympathize with your plight. However, you can certainly use the PDFs in the thuum.org Library even when you're offline.

Here is the 53-page Learning Dovahzul PDF link which goes over everything that is covered in the Lessons section on the site, albeit in a handy and easy-to-read PDF format. 

If you want to have a comprehensive dictionary of all words created by the community for Legacy Dovahzul, here is the 4th edition Dovahzul Dictionary PDF link for you. It's 256 pages and has a lot of Legacy words, as well as cheat sheets for Dovahzul grammar. Keep in mind that Legacy Dovahzul is no longer maintained by the community, and it is only ever used on this site. I personally recommend trying to learn the Canon Dictionary first, since it is much easier and can be understood outside of thuum.org.