Hello!
Can i use Grove Ultrasonic Ranger sensor on RePhone Kit Create?
If you can spare one trigger pin and an interrupt pin, yes 
When i use hc-sr04 sensor with spared Trigger and Echo pins what are the contacts of GSM Breakout i can use
If you can spare one trigger pin and an interrupt pin, yes
When i use hc-sr04 sensor with spared Trigger and Echo pins what are the contacts of GSM Breakout i can use