Why not write some instructions then? If that’s the problem…
Also, your one piece of evidence flies in the face of the bigger picture, where apps supporting iMessage functionality have seen serious spikes in downloads since iOS 10 went live.
iOS 10 may have only reached roughly half of iPhones and iPads so far, but developers who readied their mobile apps for…techcrunch.com
So, no, it’s not “hurting developers”, it’s hurt one developer that won’t add instructions.
Also, Cloak seems to pretty closely mimic Apple’s built-in “Invisible Ink” feature, so, you know, good luck with it even staying available at all.