Insightly is a web-based project and Customer Relationship Management (CRM) application that integrates with Google Apps via a Gmail contextual gadget and Google Docs support.
Unique to Insightly is the concept of "linking": any element in the system can be associated with another element: projects, tasks, contacts, organizations, events, emails, opportunities. The link describes the role. For example, contacts can be associated with other contacts as "colleague", "was referred to / referred" etc., or as a custom relationship. Tasks cannot be associated with tasks, and Insightly lacks task dependencies or Gantt charts. A task can be linked to multiple projects via the "Link" feature, but there is no drag-and-drop. Tasks can only be assigned to one Insightly user, and cannot have a start or due time (only a date). Insightly, however, support events, where the time can be set.... More Info »
Insightly supports tags for opportunities, projects, contacts, organizations, and emails. However, tags for projects are totally separate from tags for contacts, and searches for the tag name don't find any.
Contacts, projects, opportunities, tasks support custom fields, but only up to 10, and only text, drop-down and date (compare to Podio or Solve360). Projects, like contacts, can have a photo/image.
The Gmail contextual gadget can be used to add tasks, projects, opportunities, and emails, but not contacts. Email notifications include a daily email reminder with overdue tasks.
There is no social media integration, but for organizations, there is an event tab with Google search items.
Insightly lacks Gantt charts and an API (http://support.insight.ly/entries/383383-api-external-information-integration). Comments, notes, task details do not support rich formating, only plain text. Email import from Gmail misses formatting. The user community was deleted in January 2012.