About a year ago I mentioned a library providing an alternative to NSTimer that works with GCD queues.
Here’s an objective-c library from Mohammad Islam called Easy Timeline that allows you to create timelines for those times when a single NSTimer isn’t enough or you want to pause things and resume later.
Easy Timeline allows you to set up events that can occur at different time intervals, add events to the timeline while it is running, change the duration of time ticks, pause and resume the timeline using a blocks based or delegate based syntax.
This diagram from the read me illustrates how you might set up a sequence of events:
You can find EasyTimeline on Github here.
An excellent way to handle multiple timed events.