A central manager receives tick subscription requests from subscribers, including a requested period and an allowable variance. The manager selects a group period for a group of requests, based on requested period(s) and allowable variance(s). In some cases, the group period is not a divisor of every requested period but nonetheless provides at least one tick within the allowable variance of each requested period. Ticks may be issued by invoking a callback function. Ticks may be issued in a priority order based on the subscriber's category, e.g., whether it is a user-interface process. An application platform may send a tick subscription request on behalf of an application process, e.g., a mobile device platform may submit subscription requests for processes which execute on a mobile computing device. Tick subscription requests may be sent during application execution, e.g., while the application's user interface is being built or modified.