To be able to test the functionality of myTracks you can download a 30 days trial version. This version has (nearly) the complete feature set. The iCloud support is missing in the trial version because Apple only allows apps from the App Store to access iCloud.
If you need some example GPS tracks please download the following GPX file and import it in myTracks:
In case you bought a classic myTracks 2.x license outside of Mac App Store you can still download the latest version here: