that was my first thought, too.
It would not be so hard, since they asked you to contact them regarding the iPhone app. If you called them, they know who you are now - if they had not figured that out before.

Just a few marginal delays would very likely not be enough to justify such an effort to keep you happy with multiple presents, so my guess is as well that they're paying you back in return for the never ending issues with the app, and for the loss of your anonymity on this forum towards them.
The official reason will of course remain that it has to do with any service shortfall or delay which you've experienced, because otherwise it might be seen as an attempt to bribe you, and I'm sure they would never do that...

I'm happy for you that they're so nice to you, and you surely deserved it, too.
I would be even happier if they'd also spent at least some effort and money to fix the underlying issue.