IDC said Apple is now within striking distance of the established wearables market leader, Fitbit. The research company said Apple shipped a total of 3.6 million units in the second quarter of 2015, just 0.8 million units behind Fitbit's 4.4 million units. Total shipment volume for the quarter came to 18.1 million units, up 223.2 per cent from the 5.6 million units shipped in the second quarter of 2014. Apple's arrival had the greatest impact on the smart wearables category, or those devices capable of running third-party applications. IDC noted that about two of every three smart wearables shipped this quarter was an Apple Watch. Report