Storyline Player app push notifications?

For a client project I want to select Storyline as my tool of choice. It does everything I need: looks good, stable, not too complex, very customizable, reporting.... but... One requirement I can't seem to meet and the client insists on it. The setup is that we use mobile content as some sort of "instant response training": the learner receives a tiny learning nugget and needs to consume it within 15 minutes or so and answer a question. Part of the metrics is how many learners meet this deadline.

But how do I notify the learner that a new mini-course has arrived? iOS push notifications would be great... but can Storyline do this somehow? Maybe in combination with a certain delivery platform?

I tried suggesting notifications via e-mail but that was not accepted... most learners receive numerous e-mails on a day and have strategies of not responding to those immediately.

Thanks for any good ideas.