FreedomPop, the Los Angeles-based startup whose mobile phone plans offer free texts, calls, and data, will give its subscribers access to the AT&T network starting today.

Previously only available available on the Sprint network, FreedomPop's expansion to AT&T will offer its customers more choices for how to use their free data, including a new mobile hotspot offering or the option to buy a SIM card for use in an existing device.

The AT&T hotspot costs $29.99, and comes with 2GB of free data. The SIM card, meanwhile, is $10, and can be used with any GSM-compatible phone.

To keep costs down, FreedomPop's service model relies heavily on Wi-Fi access and zero-rating, the practice of allowing access to some apps and services without consuming your data allotment. Many of its SIM card plans include unlimited use of WhatsApp, for instance.

But potential FreedomPop subscribers excited by the possibility of using AT&T's network for free should note the service's many caveats. With just 200 minutes, 500 text messages, and 200MB of data, the free plan is extremely limited. Paid options can get expensive, too, with the top-of-the-line hotspot plan offering 10GB of data for $74.99 per month. While it's unclear if those rates will apply to AT&T plans, they're worth comparing with your current bill if you're an AT&T subscriber who's thinking about switching.

FreedomPop launched a $5 per month Wi-Fi only plan in 2015, which in addition to unlimited data offers subscribers free texts and calls when connected to a participating Wi-Fi hotspot. At the time, the company's CEO explained that FreedomPop's plans are intended for "cash-strapped consumers."