Apple (AAPL -1.17%) is likely just months away from taking the wraps off of its expected iWatch. The Mac maker could easily sell tens of millions of units of its smartwatch, which represents a significant opportunity for any component suppliers lucky enough to win a spot. Looking at recent Apple devices, investors can speculate on companies that Apple may tap as vendors. Possible names include NXP Semiconductor (NXPI -1.74%), Universal Display (OLED -0.04%), STMicroelectronics (STM -0.52%), and OMRON Global.