So how does this app do it, facilitate a bridge to Apple iMessaging Servers, when thus far in the past I think only a few shady approaches were possible if one didn't actually have an iOS device?
They've got Mac mini based server farms, when you log into the app you actually log into your Apple account on their mac farm. The security risks should be pretty obvious, but then, so are the security flaws of falling back to SMS to message an iPerson.
I wonder if that is allowed based on AppleID/Account terms of service? I also wonder if Apple could disrupt such by slight tweaks to their iMessaging protocol? The last approach I heard about sounded similar but was hosted in a questionable country.
I don't know if it's against Apple's t&cs, but I would put money on the answer being yes. I'm not sure Apple could block it without also blocking iPeople from accessing iMessage on their Macs legitimately... They may not want to. I've got a feeling that they will open upp a bit in the next few years. Not because of the "pressure" Google is putting on them, but with 87% of youngs using iPhones in the US, they're going to be pushing into regulatory issues if they aren't careful.
They'll probably just wait until they think there is enough "investment" by Nothing Phone company, then roll out a critical not optional update to Macs that includes something like putting the iMessages into a slightly different folder or Database structure (not even sure if that is a thing on Macs), then poof, disrupted for a while (for the Nothing Phone App), until the Nothing Phone company adjusts their bridging software. Apple doing that strategically a few times (cat and mouse game like used to happen with SatTV hacking) will probably turn off most normal users from the bridging service/app.
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