We recently launched mobile SDKs for iOS and Android at Snowplow (https://github.com/snowplow/snowplow), so that's probably the easier route to go than a full-blown custom build :-)
Yeah seems good and I will check it in depth. It seems not provided out of the box, but I assume I can use MS SQL/HDInsight as a backend, instead of Redshift? Maybe you should consider including Azure as an infrastructure partner. I'm a consultant in the non-valley space (rest of the world). Lots of folks like me are looking for what you've developed. Most are pretty big MS fanboys. Just saying :)