Hi,
In Android 6.0 Google introduced a new feature called “Default phone app” .
✔ i can prepare an app with xamarin android native for your purpose.
✔ Xamarin Android developer is my expert
✔ UI/UX Design (Photoshop,Corel,Freehand, Illustrator,...) for your dialer
✔ 100% Satisfaction.
✔ On Time Delivery.
I have done many app project with xamarin (IOS , Android)
I have +15 years of experience in software development
the biggest project is for US, an app (and site) similar to UBER that i will send to you the project link.
(searching Saviway on appstore)
my apps Screenshot:
https://www.freelancer.com/u/obazri/portfolio/Mobile-Application-IOSAndroidXamarin-8735693?w=f&ngsw-bypass=
let's start to work together.