I am not sure if this plan is still available, but I am on $30/month no contract plan. This has unlim. data, text and 100 voice minutes. It works perfectly with unlocked Nexus 4 which I got in Jan 2012. I'm never going back to contracts anymore.
My wife lost her T-Mobile G Slate tablet and she was going to replace it with a WiFi only one, so she called T-Mobile to cancel the data plan. Even though it was not covered by insurance, they sent her a replacement (upgraded to Samsung Galaxy Tab) and they converted the plan to a 200MB 4G/month plan for no monthly charge. That is great customer service.
This plan is still available I believe as I got this plan at the beginning of December.
All you need to do is get a new sim card from T-mobile.com which is usually close to free. And then activate the sim card online. Going through the steps you get to select your prepaid plan, and the $30 a month plan is one of the options.
I am not sure if this plan is still available, but I am on $30/month no contract plan. This has unlim. data, text and 100 voice minutes. It works perfectly with unlocked Nexus 4 which I got in Jan 2012. I'm never going back to contracts anymore.