I am working on an in-house, iOS app that will need read-only access to a SQL Server with multiple databases. I know the stock answer here is \"write some web services\", bu
Actually the easiest way is to create a MVC 3 or 4 asp.net web application. call the web methods. You don't need any API to pay for.
I use SBJson to serialize domain object and then send the objects as serialized jSOn to MVC 3. It's super easy to do. I even send images with base64, so it's .net compatible.
See my blog post with sample code: http://nickturner.wordpress.com/2012/10/09/107/