Voice activated offline voice recorder Sometimes while driving or washing the dishes some idea pops up in my head while I am listening to music.

How may I record voice without touching the phone?

(Sometimes while driving in remote places I do not have Internet connection so using Siri will not work)
Audio Memos

This paid app lets you add a paid extension that allows you to have voice activated recording:


  
  Voice activated rec. - stop recording silence.
  


If you don't like IAPs, then you can download Audio Memos Pro from the same author (but it's more expensive than Audio Memos + IAP price.

Smart Recorder

This paid app also lets you have voice activated recording:


  
  Auto pause/voice activated recording