Mobile application developer. Xamarin and .NET MAUI specialist (Android and iOS). Consulting, design and development services. New, existing and distressed projects. Published on the Apple App Store and Google Play Store. 25+ years experience with wireless and mobile applications. 10+ years with Android and iOS. 7+ years with Xamarin/.NET.ACTIVE PROJECTS:Mobile payments -- .NET MAUI migration from Xamarin native (Android and iOS), CommunityToolkit.Mvvm, Auth0 authentication, Single Sign On (SSO), Refit for web services.Mobile payments -- Xamarin (Android & iOS), OpenId Connect (OIDC), Auth0 authentication, Amazon Cognito, Azure AD B2C, Microsoft Authentication Library (MSAL), MvvmCross, Braintree SDK, Apple Pay, Google Pay, PayPal, Venmo, ACH, credit cards, ATH Movil, location services, Apple maps, Google maps, QR code scanning, custom Xamarin bindings, Dotfuscator obfuscation, Visual Studio App Center CI/CD.Inventory/Fleet management -- .NET MAUI migration from Xamarin (Android), CommunityToolkit.Mvvm, SQLite, license plate recognition (LPR), offline operation, location services, picture taking, Dropbox, Visual Studio App Center CI/CD.Fleet management -- Xamarin (Android & iOS), MvvmCross, SQLite, Azure Notification Hubs (ANH) push, offline operation, location services, Stripe credit cards, OpenEdge (Global Payments) credit cards, picture taking, signature capture, Dropbox, xUnit automated testing, Visual Studio App Center CI/CD.RECENT/OTHER PROJECTS:Mobile Messaging -- .NET Standard (server), Azure Notification Hubs (ANH) push.Mobile Messaging -- .NET Standard (server), Twilio SDK, Twilio Studio, SMS and MMS.Financial Calculations -- .NET Standard (mobile and server), class library.Point Of Sale (POS) -- Xamarin (Android & iOS), MvvmCross, location services, Visual Studio App Center CI/CD. Social networking -- Xamarin (Android & iOS), MvvmCross, Google maps optimization, reverse-engineer legacy protocols.Inventory management -- Xamarin (Android), web services, location services, picture taking, Dropbox, binding libraries.Mobile payment -- Xamarin (Android & iOS), credit cards, location services, Apple maps, Google Maps.CRM -- Xamarin (iOS), web services.Surveys -- Xamarin (iOS), web services (Swagger.IO), binding libraries, oAuth2 authentication (Thinktecture), SQLite.Fleet management -- Java (Android), location services, offline operation, OpenEdge credit card processing, picture taking, signature capture, Dropbox, printing, barcode scanning.Trouble tickets -- Xamarin (Android & iOS), SQLite, binding libraries.