Personally yes - I always put my device into airplane mode.
Many will say they have never had a problem in 200 flights etc etc but the fact is close proximity rf can interfere with other transmitting/receiving devices due to the front end being swamped by a harmonic of the interfering device.
You may have many uneventful flights but my philosophy is why potentially risk something when that risk can be completely eliminated by a simple setting.
Aviation is all about risk mitigation
Once I've got maps downloaded on cellular network for where I'm flying I will turn my phone on airplane mode, mainly so calls/texts don't interrupt. I also quit all other apps running in the background so the GO App has all of the phone's processing power available.