Some stocks live and die by Apple (NASDAQ:AAPL) product launches, and last week it was Apple itself that took a hit. The company's shares declined in three of the four days following Tuesday's iPhone X media event.

The big winners were the smaller companies playing critical roles in Apple's new smartphone. ZAGG (NASDAQ:ZAGG) investors were happy to ride those coattails. The distributor of third-party accessories for consumer electronics saw its stock move 19.6% higher on the week. 

ZAGG screen protectors and iFrogz wireless headphones.

Image source: ZAGG.

When Apple zigs, ZAGG zags

ZAGG tends to get its biggest boost when the form factor changes for the iPhone or popular Android smartphones. A change opens the door for ZAGG to roll out InvisibleShield screen protectors and cases in new sizes. The iPhone 8 and iPhone 8 Plus will come in similar sizes to last year's iPhone 7 models, but the iPhone X takes on entirely new dimensions.

Apple's smartphones also introduce a wireless charging feature, and ZAGG wasted no time introducing a third-party wireless charging station accessory. ZAGG's mophie wireless charging base will be available just before Friday's launch of the iPhone 8 through several outlets, including Apple stores worldwide. 

ZAGG also announced a Glass+ InvisibleShield screen protector in all three smartphone sizes. Apple's tempered-glass screens tend to get sturdier with every annual iPhone update, but enough consumers have shattered their screens to the point of embracing ZAGG's niche-leading impact and scratch protection.

ZAGG stock hit a new 52-week high on Friday. The shares have been historically volatile, and last week's high finds the stock nearly tripling off last November's low. The stock has soared 106% so far in 2017.

Things were already rolling at ZAGG before last week's announcement. Revenue soared 49% last year, the biggest leap since 2011. The lion's share of that top-line pop was the result of the acquisition of mobile battery case leader mophie in early 2016, but organic growth was also positive as the iPhone 7's shift away from the headphone jack opened the door for ZAGG's iFrogz wireless headphones.

Growth has slowed since the mophie acquisition in March of last year, but ZAGG still managed to post double-digit growth in net sales -- up 15% -- in the second quarter. It remains to be seen how many of the new products that ZAGG introduced last week will catch on, but history has shown that change is usually a good thing for ZAGG and its shareholders.