I am using a list of params of type Dictionary in a Swift iOS application to hold some parameters that will eventually be passed to a we
Instead of:
var params = Dictionary()
Try:
var params = Dictionary()
Any can represent an instance of any type at all, including function types.
Documentation: https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/TypeCasting.html#//apple_ref/doc/uid/TP40014097-CH22-XID_448
In this case it appears you need a Dictionary and the service is expecting "true" as opposed to the bool value.
I recommend creating a function to convert your bool value to a String and using that to set your params["tester"].
Example:
param["tester"] = strFromBool(true)
and then define the function strFromBool to accept a bool parameter and return "true" or "false" depending on its value.