If you are looking to create the or a visual mockup: TextMe - Unlimited free texting and calling to any phone
Allows unlimited texting to the U.S. and Canada and provides multiple phone numbers within one account. Business Texting Trials no credit card
While it's unclear if you're looking for a way to send messages without a credit card or a tool to generate "fake" text image, there are several ways to do both. If you are looking to create the or
The "gold standard" for U.S. users, providing a permanent secondary number that integrates with your existing Google account. no credit card
Offers a free start with fast registration and no card required for their SMS marketing software.