Matthias Wessendorf Do you know if this https://github.com/aerogear/aerogear-unifiedpush-server/blob/master/push/src/main/java/org/jboss/aerogear/unifiedpush/message/sender/APNsPushNotificationSender.java#L161 is called for each installations or just once (I don't know the internal of the ios sender lib, does it does a bulk send or one per token?)

That could explain the weird number, the same issue has been identified for SPS, each success callback create a new variantInformation object (On Android, we only call onSuccess once all the tokens has been sent)