There are a variety of methods an employer can monitor hours of work, including requiring employees to keep time sheets, punch-in tools, automated time-and-attendance solutions, computer or mobile applications, etc.
However, please keep in mind that there may be additional legal considerations when introducing such technology. For example, Bill 88, introduces a requirement for employers who meet certain conditions to develop a policy on electronic monitoring. There are also privacy implications to consider.
This is an issue that should be analyzed by your business in consultation with your legal counsel; this is not mandated by the new legislation.