Correct/Enhance: "How do I export or import my data to/from another app?"
It's all very well to suggest Toodledo, however, Toodledo does not support subtasks (what toodledo calls subtasks, 1 level, well ...).
Enhancing this article to be less superficial might be smart.
e.g. OPML? gtasks (has subtasks, but probably not as rich in terms of fields as toodledo?), csv?
Help the new user get from somewhere else to here. For all I know, checkvist's import/export capabilities may be useful as an intermediary step.
Anywho, in the end, this FAQ answer, as it stands, isn't particularly helpful.