Explain the problem as you see it
I work extensively on mobile. We can add nodes, indent/outdent, but not move nodes up/down.
Why is this a problem for you?
Organising nodes is an essential part of my workflow, for example re-ordering tasks I need to complete in a certain order, or organising thoughts that I've jotted down in no particular order.
It's a fundamental feature of an outliner.
Suggest a solution
Press-and-hold on a node to select it and all sub-nodes, drag to desired destination, release to drop. While dragging, moving finger left/right adjusts indent. (See Workflowy implementation.)
Up/down buttons to move the currently selected node would be a half-way solution, neither as elegant nor as capable.
The ability to move a node to anywhere within the graph via a node lookup would also be useful.