This article is useful:Â http://docs.sencha.com/extjs/6.2.0/guides/core_concepts/memory_management.html
Tag: Sencha
Sencha Ext JS development tools
For many tasks: Sencha Cmd is useful
Debugging: Can use browsers’ developers tools, but some plugins will make life much easier.
For Chrome: use App Inspector
For Firefox: use Illumination, which is aware of several frameworks while debugging.
Sencha Fiddle: another debugging tool that may e helpful.