Provide the platform where the Panzer Tactics can be played.
platform refers to platform_name; the Panzer Tactics is a game name.
SELECT T4.platform_name FROM game AS T1 INNER JOIN game_publisher AS T2 ON T1.id = T2.game_id INNER JOIN game_platform AS T3 ON T2.id = T3.game_publisher_id INNER JOIN platform AS T4 ON T3.platform_id = T4.id WHERE T1.game_name = 'Panzer Tactics'