Apple is cracking the whip, according the the Wall Street Journal.

The company has insisted for a while now that it will require folks selling magazine, newspaper and other subscriptions in its App Store to only sell content through in - app purchases. Why does Apple care? Because this way Apple gets to collect a 30 percent cut of any sale.

The Wall Street Journal App and Borders Kobo App and others had been skirting these rules - but now that Apple's cracking down. The WSJ and Kobo have caved. Both apps eliminated the option of clicking to a web page and buying subscriptions or content outside the Apple's store. Google, however, stood its ground and it's app for e-books has now disappeared from the App Store.