Details on Google’s MVNO have been a bit sporadic in 2015, with a couple of leaks in January and one in March, along with Sundar Pichai’s confirmation that the service is indeed in the works. Now we’re in April and we’re getting another leak that may have revealed more details about the Google MVNO.

A Nexus 6 firmware image was recently posted on motofirmware.center, and while the original link and site aren’t available right now, a mirror of the image is available on xda-developers. According to Android Police, the image was made from an internal Google build that was distributed to testers over the air.

The image, which is build LVY47H, includes an app called Tycho that contains hints about Google’s upcoming MVNO. A “trusted source” of Android Police’s says that these details are legit, but as usual, nothing is official until Google says it is. 

The first part of this leak is the Tycho app itself. It includes the ability to pay bills, change your plan details, and even activate/cancel service or request a new phone number from within the app. Some of these features typically require you to contact your carrier or talk to another real person, so it’s notable that Tycho lets initiate them from your app.

The second aspect of the service is the plan that you’ll sign up for. The service — which is called Project Fi, though that may be just a codename — will let you sign up for the amount of minutes, messages, and data that you want. You start out with a flat rate for talk and text, then you go on a per gigabyte basis for data. What’s interesting is that Google says that it’ll refund you for whatever you don’t use, and if you do go over, you pay the same price for more.

There are a few other interesting tidbits included in this leak. For example, there are references to shared data and data-only service, and some strings suggest that you’ll be able to switch which phone you’re using with Project Fi with the press of a button. There are also references to auto-switching networks and callouts to both Sprint and T-Mobile, which backs up rumors that Google’s MVNO will switch between those networks and Wi-Fi for service. Finally, the app suggests that users will be able to buy a Nexus 6 and pay for it in installments.

If all of the information included in this leak is accurate, Google’s MVNO sounds like it will offer many features that you’d expect from a prepaid service, but with some perks to make using it easier. For example, the plan system that refunds you for what you don’t use and doesn’t charge data overages is a welcome change from regular operators. And with most MVNOs, high-end phones are typically expensive, making some consumers unable to buy them since they can’t afford to pay $600 or $700 at once. Google’s Nexus 6 financing can change that and it could also help to get more people on the latest version of Android.

Overall it’s looking like Google’s MVNO could bring some welcome changes to the mobile market. There’s no word on when it might actually launch, but Sundar Pichai teased in March that we’ll get more information on Google’s plans in the coming months. While we wait, you can read many more leaked Project Fi details at the Android Police link below.