Billing and Invoices in Studiometry are done through creating Debt/Credits, that combine to create a total balance for a Project. Debt/Credits are attached to Projects.
Any type of work or expense for a Project is considered a Debt/Credit.
To create a Debt/Credit, select Project Menu > New Debt/Credit, or click the plus (+) button below the Debt/Credit list in the main window.
You can create running timers (hourly Debt/Credits) directly from Running Timers window by clicking Start New Timer.
On Mac OS, you can set up the Status Item to create a new timer when a Project is selected. This can be setup in the Preferences Window under the System Syncing pane.
To Re-Assign a Debt/Credit to another Project, use the Edit Menu > Copy and Edit Menu > Paste commands.