I'd had enough of AT&T, so I made the switch to Cape today, drawn by features and a 30-day discounted trial. It's still in beta, and it shows, but it's impressive.
While signup/payment is credit card only, they ask only for your card number and zip code. Stripe tokenizes the payment and Cape holds no data. After payment, you're assigned a 12-character access number, a la Mullvad.
You install their app from the Apple App Store or Play Store. They also suggest Aurora, which is a nice signal. While they officially support nostr:nprofile1qqs9g69ua6m5ec6ukstnmnyewj7a4j0gjjn5hu75f7w23d64gczunmgpz4mhxue69uhhyetvv9ujumt0wd68ytnsw43q4gnztg (based), they do note that Play Services are required for their app to work, which is required to acquire their eSIM. Maybe nostr:nprofile1qqstnr0dfn4w5grepk7t8sc5qp5jqzwnf3lejf7zs6p44xdhfqd9cgsppemhxue69uhkummn9ekx7mp0qywhwumn8ghj7mn0wd68ytnzd96xxmmfdejhytnnda3kjctv9ulj6hdh can comment on why that might be.
One hitch is getting to the point in their app where you enter your account code. Graphene doesn't scan QRs and open associated URLs out of the box, so you'll need an app for that.
Once in the thoughtfully designed app, your12-word seed phrase is generated; excellent UX at this phase. This is how you recover your account, if needed.
Then you download your eSIM. You must manually add a new access point (APN) via copy-paste, which could be error prone. Reboot, and you should be good to go.
One thing they do not make clear up front: they haven't yet rolled out RCS for GrapheneOS/Android. When I grumbled about this, they offered me a 30% discount for 6 months. Not bad.
DYOR, always, but here's a referral code for $10 off per month.
https://cape.co/get-cape?referral=PIBC6TKY