Yes! Hubstaff currently has an iOS app that you can download here and read more about here.
We also have an Android app that can be downloaded here.
For more information about our mobile time tracking app, check out this article: http://support.hubstaff.com/hubstaff-mobile-app-location-tracking/
Note: Due to the limitations placed by mobile providers, the app can only track time and locations and does not have the capability to record screenshots as well as activity levels.