All apps you download from the App Store: both Free and Paid are displayed in your Purchase List. Since you downloaded the 4shared app, you can also see in your Purchase List.
No, the 4shared app is 100% free. Thus, you weren't charged any money.
No, it doesn't. Purchase history has nothing to do with your iPhone capacity. But if you want to clear the Purchase List for any reason, you can do it yourself.
It's easy to say, "Please remove app from Purchase List" in the App Store review. But reviews only convey feedback on the app or service. App developers are not allowed to erase your purchase list. In fact, the purchase list can only be deleted directly by the user.
Occasionally, no matter how many items you’re sliding the app, the Hide button does not appear.
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If you don't see the X sign, move the cursor to the top-left of the icon. When the cursor turns into a hand to indicate there is a link, click here [the top-left corner area] to open the dialog window.