You can view your iTunes spending directly inside Rocket Money. Here's how:
Open Rocket Money and go to the "Recurring" tab
In the upper right, click on the "List View" icon towards the upper right of that screen (it looks like a square with 3 lines in it)
In your list, scroll down and tap on "iTunes"
From the iTunes page, you can see a historical chart of your iTunes spending.
To view the breakdown of your iTunes subscriptions and to cancel subscriptions, tap the "Manage Subscription" button on that page.