Unfortunately, at this time we do not offer any full way to backup/archive your projects or tasks to a computer or device. We do create daily backups of your data and is on one of the most secure servers out there (amazing web services).
We do have the ability to "export as template" which you can find in the right click menu of a Project, and it's saved as a txt file. This could be used as a backup but of course you have to do each project one by one. These will not be kept updated unless you do so again as well.
Thank you Brendon, I'll schedule the export on a regular basis, just to be extra safe. I love the app, I live by it!