T-Mobile has launched a new eSIM app for use on the iPhone XS, iPhone XS Max and iPhone XR with iOS 12.1.1. Unfortunately for existing postpaid users, they will have to wait for service plans to be compatible with eSIM as it seems like the Un-carrier is trialing the technology with prepaid plans first.

The T-Mobile eSIM app supports two regular-use plans — the $40 Simply Prepaid plan with 10GB of LTE data and a $70 T-Mobile ONE Prepaid plan with a significantly higher throttling threshold — plus its 21-day Tourist Plan with 1,000 minutes, unlimited teting and 2GB of LTE data for $30.

The company is promoting eSIM use for tourists, people who want a second line of service on the same phone and anyone who wants to try the network out. More plans, including postpaid plans, may be added on later.

Separately, the company is bringing back its Black Friday deal — it is offering up to $750 off a second phone with the addition of a line of service (or two lines for new customers. Customers must also trade in their existing device in good condition. That makes phones like the OnePlus 6T, LG V40 ThinQ, iPhone XR and Galaxy S9 free.

Details on both the deal and the eSIM app are available below this story.