1) In person lunch interview - 1 hour
2) On-site - 4-6 hours
3) Rejection - priceless
Overall, everyone was very friendly. The office is great. Lunch is quite decent. A lot of weight is placed on cultural fit, so be friendly and open.
After preparing for more difficult interview questions, I got completely thrown off track when asked to implement a couple of very basic iOS tasks -- think table/collection views and autolayout. Also think no boilerplate code to even get the app on screen. For an experienced engineer, who may be used to adding features to an existing application or use Xcode boilerplate code (read: most people), this was annoying. Not a good measure of anything, in my opinion.
Was disappointed, because I don't think the two questions I flubbed were a good representation of day-to-day skills. Doubly disappointed, because I was told there would be a paired-coding session involving debugging, etc., which sounded a lot more worthwhile.
At end of day: prepared for a senior position, was thrown by junior/entry-level questions.