Is it possible to allocate employee time against a project or job?

Employees work during the day on various projects. Is it possible to mark time against a project on the field check-in using the app?

To support this, I will need to extend existing feature first.

But before that, I will need to know more details about your use case first.

Was just looking for a way to track hours of employees against jobs for future invoicing

I know, but I need to know how is your use case, such as what do you expect your employees to do with this feature, and how do you extract report or data from this module to support your invoicing etc.