It should allow to work off line
I've seen many android apps that can work offline but they always ask for working internet connection in order to work. I.e. Shadow Fight 2 (https://fineapkapps.com/download-shadow-fight-2-titan-mod-apk/) etc. The developers of these kinds of apps do this in order to earn extra money. But some times user feel problem while they have no internet connection. Sometimes a person goes out of his or her home and they are unable to connect to the internet. Under these conditions they feel a great amount of problem.
Because of this Point I cant completely migrate from Trello...
Petr Musil commented
Trello can work offline.
My workaround: I have configured Flow to use Trello >>> Planner template for a pre-defined Trello board/list. When offline, I use Trello to create a new task in that special board/list. Once I become online again, Trello syncs the mobile version with the cloud, creating a new task there, which also triggers the Trello >>> Planner Flow, and ultimately generates a Planner task
I use this app to organise my work programme but may have to stop as I am often in rural locations with poor network coverage so cannot access Planner.