What We Do

Cardinsoft develops native inbox add-ons for Gmail and Outlook. 

Google and Microsoft added added modern JavaScript-based inbox add-on frameworks to Gmail and Outlook respectively in 2017. They work on web, mobile, and in the case of Outlook, the desktop apps for PC and Mac.  These inbox add-ons replace the legacy Firefox and Chrome extensions for Gmail and COM extensions for Outlook, bringing much-improved cross-platform support and security.

Many add-ons share the same use-case (e.g. provide contact details from your CRM system), and therefore follow a similar design pattern.  Supporting the most common use cases (e.g. CRM contact retrieval and edit), Cardinsoft has developed an SDK for Gmail and Outlook add-ons that reduces the time needed to spec and build and add-on by an order of magnitude.  The SDK includes templates of full working add-ons which implement specific use cases (e.g. CRM Create, Edit, Update, and Delete) that can be quickly customized with your organization logo, name, API specifics, and business rules.

Cardinsoft provides the following to help you expedite the development of your add-on:

Full source code

This includes both our use-case specific templates and libraries abstracting common functions for easy UI development. Well-documented source code means your development team can come up to speed quickly and customize the add-on to meet your specific needs.

Same code runs in both Gmail and Outlook

Our libraries enable you to develop add-on code for Gmail and run that same code in Outlook with little to no change. We do this by providing a similar interface to the Gmail CardService framework, in Outlook. In addition to speeding development, this results in a nearly identical look and feel across Gmail and Outlook email clients, reducing documentation and support costs.

Professional services

Our team of experts can do anything from providing tips and tricks to your development team as advisors through to building the entire add-on and taking it through the Gmail and Outlook add-on store approval processes. 

There is no need to reinvent the wheel.  Cardinsoft can help you save time/money, reduce risk, and provide your users with a great experience out of the box.  Drop us a note at info@cardinsoft.com and we’d be happy to discuss the specifics of your project and provide a quote.  Even if you don’t ultimately use any of our professional services or SDK, we are happy to share our insights and help point you in the right direction.


Close CRM

Close CRM

Our Close add-on template is a great example of a typical CRM Add-on use-case. Highlights of the add-on design features are outlined below. 

Core Features

Welcome screen

It is critical for a good first user experience to explain briefly what the add-on is, and what it is supposed to do, before the user has even configured anything.  


The add-on will need to be authorized to the user’s account using either an API key or an Oauth flow.  In the case of Close, an API key is used so the welcome screen explains how the user can obtain their API key and provides a link to get there.

This hand-holding is critical as confusion about what an API key is and where to find it can result in support incidents and frustrated users.


All settings are contained in a single card which can be configured at setup and accessed later from the menu.  

It is often preferable to allow the user to decide how much related information to query as some of these API calls can be time consuming and users often prefer less information faster, especially since they always have the option to deep link to the app itself.


Display matching CRM records

If a lead or contact (in contact view) matches sender’s or primary recipient’s email address, info available will be displayed in the first section.

Edit Leads in CRM

Add new

If no matching records are found in the CRM, the user is prompted to create one using the information from the email.

Create first opportunity

If you turned on creation of an initial opportunity in settings, if no leads match the opened email, you will have an option to create an opportunity bundled with the newly created lead.

Initial opportunity creation is available in lead view only!

Edit info

Most of the lead and contact info can be edited directly in the add-on – and updates can be made incrementally without the need to enter full edit mode.

Perform Actions

Close integration has a number of actions that you can perform on a matched lead or contact (they can be found on the topmost section of the display)

Multiple matching CRM records

If more than one lead matched the open email, you will be able to traverse results by clicking on back or forward arrow (leads and contacts are sorted by last updated time)

Refresh results

If you made changes in Close app or just want to get the most recent info after being offline for a while, just click on the refresh icons to query your account again.

Send bulk updates

By default, all updates made to lead or contact are applied immediately. If you turned off this feature in settings, you can make all the changes you need and then send them to your account when ready.

Remove records

If you added one by mistake or a lead is no longer relevant, it can be removed.  The add-on will ask you for confirmation to prevent accidental sensitive changes to your account.

View extra info

If available, lead and contact will have additional info displayed in several initially collapsed sections, including taks, opportunities, contacts (for lead view), activities and custom fields).

View activities

Lead or contact activities (sorted from newest to latest) are displayed in a dedicated section and can be incrementally fetched as needed (initially, 8 latest ones will be shown).

Each activity type has distinct representation and additional info to display if available (e.g. duration for calls, template name and deeplink for emails).

Edit email templates
Traverse multiple-page activity lists


Invalid API key

If you provided an invalid API key or lost access to your account, the Add-on will promptly notify you and provide with helpful tips on how to proceed.

Limit Reached

If your current plan doesn’t allow you to make more calls to Close API, you can wait until daily limit resets or upgade to a plan with a higher cap.