For the desktop users: I am working on something that may help (Linux/Windows users for now)
It's called Focus|Project for Trello it's still in development (long story :) ) but I also am a user (on Ubuntu).
See https://f-p.app
It is not meant to be a replacement for Trello at all, but an addition: expect a "single card + list grid view" rather than a board or timeline.
Do expect past board data + a growing offline mode, image editing, dark UI and a battery-friendly nature rather than collaboration, chat, power-ups & animations.
Feature-wise it might be more or less used to bridge an hour or two of a journey or unexpected outage, assuming the project planning part is mostly already done (eg. card members cannot be edited yet) and the app is in regular (not necessarily continuous) use - i.e. can update.
There are silly mistakes/bugs at this point, partly as I have been going for prototyping features for a while to see if things will work - I think it's soon ready to aim for a bit more seriousness again.
For now, I suppose it's better than nothing - do feel free to
Try! (of course)
Let me know your biggest pain point (only one please! I am snowed under ... I can't help spotting problems myself :) if there's visible interest - there's development I guess)
Show interest (but not be too hard - e.g. you may need to restart it after going back online to see the changes)
Grab a license (on Win), whether free, or even - somewhat speculatively - a pro and thereby support development