The repo have files that contain powerfx snippets applicable to canvas and model driven apps

Snippet can be used to check validate different types of data input on canvas app
Data Input Validation
Blog page with examples

Check and display numbers of days/months/years between two date in canvas app
Date Difference
Blog page with examples

Creating an activivty timer inside Canvas App
Timer Control Canvas App

Editable grid canvas app

HTML Table

webresource JS

webresource JS