Transforming Office Productivity
Through Custom Add-ins
Professional Microsoft Office and Google Workspace development services tailored to automate workflows and boost business efficiency.
Who We Are
MSOfficeAddin.com is a specialized development agency...
500+
Projects Delivered
98%
Satisfaction Rate
10+
Years Experience
30+
Countries Served
Why Choose Us
- Office.js Specialists — 500+ add-ins delivered since 2015
- Delivery in 2–8 weeks (standard) or 6–12 weeks (Graph-integrated)
- Azure AD SSO, MSAL OBO flow, Microsoft Graph security on every project
- Registered AppSource Publisher — avg. 3–7 day certification turnaround
- 50+ VSTO-to-Office.js migrations completed for enterprise clients
What We Do
Office Add-ins Development
Custom Microsoft Office 365 add-in development for Excel, Word, Outlook, PowerPoint, SharePoint, and Teams. Hire certified Office.js developers for enterprise automation, AppSource publishing, and VSTO migration.
Specialized Solutions
Google Workspace Add-ons
Custom Google Workspace add-on development for Sheets, Docs, Gmail, and Drive. Professional Apps Script and REST API solutions for Google Workspace automation.
Specialized Solutions
Authentication & Identity
Secure authentication development services including Microsoft SSO, Azure AD, OAuth 2.0, OpenID Connect, MFA, and role-based access control for web and enterprise Office 365 applications.
Specialized Solutions
AppSource Publishing Services
End-to-end Microsoft AppSource publishing and certification support for Office add-ins. We handle code review, manifest optimization, compliance validation, and submission — getting your add-in approved on the first attempt.
Our Delivery Process
A structured approach to turning requirements into enterprise solutions.
Discovery
Scoping call + workflow analysis. We document Office.js API requirements and define the manifest, permissions, and authentication model before writing a line of code.
Design
Fluent UI wireframes and task-pane architecture. We align on API requirement sets (e.g., ExcelApi 1.14, Mailbox 1.10) to ensure cross-version compatibility.
Build
Agile sprints using Office.js, React, TypeScript, and Azure. Daily builds are testable via sideloading in your own Microsoft 365 tenant.
Deploy
Security audit, manifest validation, and AppSource submission. Microsoft review typically completes in 3–7 business days.
Support
Post-launch monitoring and compatibility updates for new Microsoft 365 releases. Response time: 24 business hours.