How can I test my App in Android device?

Hi,
I am absolutely newbie in this part of the world and want to start by saying sorry for my silliest of questions!

I have created an App in RareWire ("Hello World") and now want it to see on my Android device. Installed Fusebox already.

I went on to "Publish" page and selected "Build Your App for Android" option which is showing "Free during beta". But it is not letting me go pass this page and saying "Invalid credit card information". If it is free why I am asked for this?

How can I test my App on the device? Do I have to pay even for testing ?

Regards,
Subrata Sarkar