Kosher phone also means no internet, no email, etc. It is just a phone. Again, when we speak about convenience remember the question was posed about an 11th grade yeshiva bochur not the general public. Does an 11th grade yeshiva bochur “need” texting. I think the general consensus is “no he does not need it”. Should he get it? The general consensus is “it would be better if he didn’t at this time”.
The other discussion which veered off topic was if texting is useful and convenient or has it destroyed the basic use of conversation. The general consensus is “yes” to both.