Widget : many2one_avatar_user 

This widget depends on many2one field of res.users 

Module : sale_management 

Field Type : Many2one

Widget : char_emojis, text_emojis 

This widget depends on Char and Text fields, if you are using char field type use widget=”char_emojis” and if you are using char field type use widget=”text_emojis” 

Module : mass_mailing

Field Type : Char or Text

Widget : remaining_days 

This widget depends on datetime field, it will calculate remaining days 

Module : purchase 

Field Type : Datetime

Widget : Countdown 

Drag and drop widget from Website 

Module : website

Widget : color_picker 

This widget depends on Integer field of state

Module : sale_management 

Field Type : Integer

Widget : kanban_activity 

This widget depends on one2many relation field of mail.activity object, you may use it as follows

<field name="activity_ids" widget="kanban_activity" optional="show"/>

Module : sale_management 

Field Type : one2many

Widget : many2one_avatar_employee

This widget depends on relational field of hr.employee

Module : hr_expense

Field Type : Many2one

Widget : product_discount

This widget depends on float field

Module : sale_management 

Field Type : Float

Widget : grouped_view_widget

This widget depends on text field

Module : account 

Field Type : Text

Widget : task_with_hours

This widget depends on many2one field of project.task

Module : hr_timesheet

Field Type : many2one

Widget : timesheet_uom_no_toggle

This widget depends on float field

Module : project

Field Type : Float

Widget : forecast_widget

This widget depends on float field

Module : stock

Field Type : Float

 Widget : stock_rescheduling_popover

This widget depends on char field

Module : mrp

Field Type : Char