This may be planned or in work, but since the map had a large change somewhat recently this suggestion is now (now/a few weeks ago) relevant- a note on a pokemon's card of where it was caught, or the other way around, a list of what you've caught in each tile when you click on it on the map. This note could be phrased like the note of a player's location in the Friends tab. Somewhat small (maybe, maybe not, I'm no programmer), but not really that important- just an idea.