Few years ago, I tried slowly (the phone app), it's really one of the best experiences with phone apps, I had exchanging from pen-pals across the globe and felt something, now I thought a web app can be cool, and vibe coded the first minimal version. Later it can be p2p by the way (totally serverless) and with encryption.
I will set the Github repo to public later because apparently yesterday I used Github desktop and it uploads code as private by default.