From a recent Austin American-Statesman article on mobile app companies in Austin, here is their list in order of employee count and with some example clients listed:
1. Mutual Mobile -> Audi, Cisco, Gowalla, Google, Dell
2. Digby -> Home Depot, Brooks Brothers, Toys R Us, Wet seal, Costco
3. Chaotic Moon -> Microsoft, Game Studio, ‘Sesame Street’, News Corp., Groupon
3. Phunware -> Discovery Channel, PetsMD
4. Tabbed Out -> restaurants and bars -> partnered with point-of-sale systems company Micro Systems
5. Unwired Nation -> no clients listed but their project converts websites into pages easily viewed on smart phones
Original article: New generation is making Austin a mobile Internet hot spot