About
One crossing, done properly.
Crossferry is a small US team of senior mobile engineers with a single specialism: taking a Xamarin app that can no longer ship to the app stores and getting it shipping again — first as a compliant release, then as a migrated .NET MAUI codebase.
Who we work with
US companies, roughly fifty to two thousand people, whose field, logistics, healthcare, utility or internal line-of-business app was built in Xamarin.Forms somewhere between 2016 and 2022. There are usually one to three .NET developers maintaining it part-time, and the people who originally wrote the mobile code have gone. The person who calls us is an engineering manager, a director of IT, or a product owner with a store deadline, an OS-support ticket, or a security review of an unsupported framework.
These apps are rarely glamorous and they are frequently load-bearing. A delivery app that stops working is a company that stops delivering.
What makes this a specialism
Xamarin.Forms to .NET MAUI is not a version upgrade with a longer changelog. It is a rehost of the UI layer — custom renderers become handlers, the project structure changes, and a decade of third-party controls and native bindings have to be assessed one at a time. A team doing it for the first time meets those problems in sequence and discovers each one at the worst moment. We have met them before, and the value is knowing which of them are genuinely hard and which just look hard.
The other half of the specialism is the store. Apple and Google both raise SDK and target-API requirements on a schedule, and an app built on an unsupported framework hits those requirements from the wrong side. Getting a build through review is its own skill, and it is usually the urgent part.
What we are not
We are not a staffed-up offshore pod, and we are not a firm that quotes a full rewrite for every app it sees. We are also not going to tell you Xamarin has a future. It does not; support ended in May 2024. What it has is a large installed base of apps that still earn their keep, and a supported place to go.
How we work
Hourly time and materials, senior US engineers, as project engagements or as staff augmentation. The method is written up in How We Work, and the reasoning behind each service is on the services pages. If you would rather read something technical first, the tutorials are the same material we apply on engagements.