When Apple Inc. (NASDAQ:AAPL) unveils its anticipated iWatch on Tuesday, you can rest assured that there will be an app for that. The tech giant is reportedly readying a robust software marketplace for the wearable much like the one for its iPhones, and Facebook Inc. (NASDAQ:FB) is among the companies that got early access to iWatch software, according to a report Monday from 9to5Mac.

The iWatch software is based on the iOS operating system and will support a number of third-party apps, according to the report. Apple is preparing an app store for the wearable, but so far it's not clear whether it will be entirely separate or a special section on the main one.

The companies were under a strict non-disclosure agreement but were given access in order to develop apps that Apple could demonstrate at its much-anticipated iWatch unveiling on Tuesday. In the past, Apple has distributed early software development kits (SDKs) to third parties to have apps ready for such events.

The report confirmed an early 2015 release date for the iWatch. Although Apple will announce the iWatch Tuesday with some pricing and feature details, the wearable will not ship to consumers until next year. This will give developers time to prepare more apps for the iWatch and retailers time to ready their point-of-sale systems for an expected wireless payment system based on near field communication (NFC), which will be supported by hardware in the iWatch and iPhone 6. Apple Stores rolled out a new NFC-based system on Monday, reportedly in anticipation of the event Tuesday.

Apple announced iOS 8, the latest version of its iPhone software, in June alongside a new software framework called HealthKit that aims to organize fitness data. HealthKit is expected to track information from the iWatch's sensors, which reportedly include sensors that detect heartbeats and motion and analyze sweat. GPS-based maps are also expected to be a key component of the iWatch.