iMessage is no longer in existence either. It’s now called Messages.

The reason that I’m asking about Allo is that a flight attendant friend recommended it. She claims that it works on TATL & TPAC flights without having to purchase wi-fi. It’s well known that Messages is not going to work on widebodies on overseas flights unless you purchase wi-fi. And, even then, wi-fi reliability can be spotty. I’m not sure that I really want to do much, if any, texting mid-flight, but I am the curious type and wanted more info about Allo usage during flights.