Is there a web app for making API calls?

Question

Is there an online application that can be used to test out an API?

I am interested in one that supports a REST API with basic authentication. I know there is a Firefox plugin that I could use for this, but was wondering if there is a web app.

Answer 1

If it's an OData endpoint, you can use the excellent OData Explorer:
http://www.silverlight.net/content/samples/odataexplorer/

Or the latest version of LinqPad which supports OData data sources:
http://www.linqpad.net/

For "generic" HTTP/REST services, you can use Fiddler to capture requests and replay them later:
http://www.fiddler2.com/fiddler2/

Answer 2

Give this a try

https://apigee.com/console/others

They support Twitter , SimpleGeo and other popular Web Services API for testing.