This was a point of contention amongst gamers who did not really appreciate how big the game was. However the good news is that if you were to update the app to the latest version, don’t be surprised if you find that you now have more storage space available on your phone. This is because reducing the app size was one of the changes that Blizzard has made in the latest update.
According to the changelog, “We’ve made some optimizations to Android distribution! This will change how Hearthstone is downloaded and will help lead to a smaller install size and smoother patching in the future.” We should note that this seems to be only applicable for the Android version of the app, so iOS users will be left out of this.
Also it should be pointed out that if you want to take advantage of the extra space, this post on Reddit is suggesting that users clear Hearthstone’s app data once they have updated the game. This can be done by going to your phone’s Settings, Apps, select Hearthstone, and then click “Clear Data”. In the meantime the latest update to the game can be downloaded via the Google Play Store.