Apple (AAPL 0.61%) 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 1.41%), Universal Display (OLED 0.80%), STMicroelectronics (STM 2.75%), and OMRON Global.