I used MSN Messenger (until MS killed and managed to kill their IM dominance), and pulled shady stunts with my phone (for example calling, saying a word, and immediately cutting connection, calling again... doing this is free for some reason).
If it was REALLY needed, I would use SMS, it was easy to make mistakes there though (a couple times I ended spending 150 USD in a month in SMS, usually in extremely stressful months where communication was essential).
The need to replace SMS was obvious, and I even had a company where I worked ask me to start researching into how to do it (this was in early 2011, I think some similar stuff already existed in US?), but this project never went anywhere.
And a technical note: doing the phone shenanigans I used to, can get you literally banned from the phone line, I was banned about 3 times (you keep your phone line, and can receive calls, but can't make any except to emergency services), but the only reason I had the phone was to do that stuff anyway (this was when I was still in school, and was the only way to communicate with my then SO, since I couldn't afford spending with real calls or SMS, because of how absurdly expensive they were... mind you, they STILL are absurdly expensive).
I used MSN Messenger (until MS killed and managed to kill their IM dominance), and pulled shady stunts with my phone (for example calling, saying a word, and immediately cutting connection, calling again... doing this is free for some reason).
If it was REALLY needed, I would use SMS, it was easy to make mistakes there though (a couple times I ended spending 150 USD in a month in SMS, usually in extremely stressful months where communication was essential).
The need to replace SMS was obvious, and I even had a company where I worked ask me to start researching into how to do it (this was in early 2011, I think some similar stuff already existed in US?), but this project never went anywhere.
And a technical note: doing the phone shenanigans I used to, can get you literally banned from the phone line, I was banned about 3 times (you keep your phone line, and can receive calls, but can't make any except to emergency services), but the only reason I had the phone was to do that stuff anyway (this was when I was still in school, and was the only way to communicate with my then SO, since I couldn't afford spending with real calls or SMS, because of how absurdly expensive they were... mind you, they STILL are absurdly expensive).