Hello, I have a sequential game (consisting of 2 apps, because "match by arrival time" happens a few pages into the survey) in which Player A makes the first move, and Player B is notified of the results.

1. When Player A makes move, they see information about Player B. (Ex. "Player B is (gender), residing in (location)) This is information propagated from a screening survey that Player B filled out in app sequence 1. My question is: how do you reference the value of the variable from the person you are paired with? 

2. Similarly, once Player A makes a decision ($ amount), this amount is communicated to Player B. Same question as above, but this would be in the same app sequence (sequence 2).

Thanks!

If you have two different apps, you need to store the player's answers in a participant field: https://otree.readthedocs.io/en/latest/rounds.html#participant-fields

Then, you can access the other player's answers by accessing their Player-Model:

# for the Page Player A can see Player B's answers
def vars_for_template(player: Player):
    player_b = player.group.get_player_by_id(2) # I suppose Player A is ID 1, Player B is ID 2 in your setup

    return dict(gender=player_b.participant.gender, location=player_b.participant.location)
    
    
And similar for the other player, though you don't necessarily need participant values (since it is the same app). If Player B will see the page before Player A makes his/her decision and the page should update, you need live pages: https://otree.readthedocs.io/en/latest/live.html

Hope that helps!