[user2342]

Is the "Core Technology Fee" applied to free Apps?

Example: I make a free App that gets very popular but has a rather seasonal character. Then there is a possibility, that many users will reinstall the App each year for a short time. Then I would have to pay the 50ct per install each year?

[urbandw311er]

Yes but only if you sell it via a third party App Store. If you continue to sell it in Apple’s you won’t have to pay the 50ct.