[luxpir]

I was also big on Trello for a good while, but wanted to come away from third-party, slightly bloaty services, so made a vertical kanban board in a plain text file. Timestamps, autocompletion, tagging etc. all present, synced to a rpi server for external access.

For tasks or events with dates I have a plaintext calendar. Similar setup there.

Have a look here: https://github.com/luxpir/plaintext-productivity

Not everyone's cup of tea, but mentions why it was developed over org-mode in the linked post.