All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad 
It is permissible to turn off the phone with a slight movement while praying, as we have already highlighted in fatwas 87472 and 72686.
If the praying person is in the standing position and the phone is ringing on the floor, then if he can turn it off with a slight movement with his foot, this is permissible, otherwise he does not bend over to turn it off because this is not a slight movement; rather, this movement invalidates the prayer if done intentionally, because it is like bowing for the bowing position or the prostration.
The owners of mobile phones should fear Allah and be keen on turning off their phones before entering the mosque so as not to harm their Muslim brothers and in order to spare the houses of Allah from these musical tones which are heard in many mosques. We also advise avoiding musical tones and limiting oneself only to ringing tones that are devoid of music because it is prohibited to listen to music from mobile phones or from any other device.
Allah knows best.
