Hi Mike,
I invite you to consider our Enterprise Stopwatch solution, which is designed to improve and expand your users’ adoption of Workfront by making it simple and convenient for everyone to track time from their browser, tablet, or smart phone, as the work occurs. Alternatively, our UberTimesheet solution takes more of an "after the fact" approach (similar to the native timesheets, but with several advantages).
Both store the hours entered directly and natively within Workfront, where you can then view and work with them As Usual.
Regards,
Doug