Allow copy/paste or cloning of transformation rules
Often some rules are similar to each other, and allowing copy/paste (with CTRL+C and CTRL+V) or cloning of a rule with a button, would enhance the productivity of the user, as they could write new rules quicker by modifying the copy of an existing rule.
In case there will still be some development work happening on Cellfie in the future, implementing this feature would be an quick and easy win. The simplest solution would be to add a "Duplicate" or "Clone" button, which would be active whenever a row in the rules table is selected, and when that button is clicked the selected rule should be duplicated (its clone should be inserted at the end of the table, or below the currently selected one), and the cloned rule should be automatically opened for editing.