I obviously support this idea. Tailuge is a ceative genius.
I see one point where this app could be improved: there could be a background process which incrementally downloads games and periodically updates the tree ( or at least offers an update to the user ). This is possible because the API has "until" and "max" parameters ( it is enough to set "until" to the earliest downloaded game and "max" to a suitable chunk size ). Seeing your opening tree incrementally building up would be a spectacle in its own right.