Looking for a Bakpack-like site/tool ,for working on a file online

Hello all,
I'm using the NextAction tool to manage my NAs. Essentially ,all info there is stored ina single HTML file .
Since I'd like to use the same file both at work and at home, I need a way of keeping the file available for editing online
(I know I can email it to myself every end of a workday and then every evening from home ,but I find it cumbersome and I'll probably forget to do this half the times ....)

This option is available in the paid Backpack subscription, but I'd rather find some free option :)