How can i make my update free for users who already have my game?

hey, i was wondering, i made an update for my app “Squashabug!”, but the people who bought my app before the update, have to pay for the update, how can i make it free only for users that already have the 1st version? [import]uid: 10827 topic_id: 5543 reply_id: 305543[/import]

is it for iOS?

If so, once a customer has the app - whether it was free or not - all updates to that app are free to them. [import]uid: 8444 topic_id: 5543 reply_id: 18788[/import]