Nothing remotely exciting in iOS 12 for Pleco, sadly, but they did announce that iOS-apps-on-Mac are coming *next* year so there is at least a solution in sight on desktop (and in the meantime it's one less thing to distract us from finishing flashcards / 4.0 
Also, current release of Pleco is bugged on iOS 12 developer beta 1; most characters appear blank in result lists, owing to an issue with color palettes. We've already fixed it + will push that fix in an update probably sometime next week, in the meantime Pleco is still usable in Night Mode if for work or other reasons you feel compelled to install that beta.
Also I'm about 99% confident now that Pleco 4.0 will require iOS 11.3 or 4 rather than iOS 12 (the dot releases because they contained some important bug fixes to PDFKit that allow us to use it for PDF reading), but since the hardware requirements haven't changed at all we aren't necessarily going to wait very long before bumping the requirement to iOS 12 just to simplify our testing / development work.
But yeah, basically good news from the Distracted Pleco front - we've got nothing to do this summer but finish 4.0 - but desktop excitement will have to wait until 2019.
Also, current release of Pleco is bugged on iOS 12 developer beta 1; most characters appear blank in result lists, owing to an issue with color palettes. We've already fixed it + will push that fix in an update probably sometime next week, in the meantime Pleco is still usable in Night Mode if for work or other reasons you feel compelled to install that beta.
Also I'm about 99% confident now that Pleco 4.0 will require iOS 11.3 or 4 rather than iOS 12 (the dot releases because they contained some important bug fixes to PDFKit that allow us to use it for PDF reading), but since the hardware requirements haven't changed at all we aren't necessarily going to wait very long before bumping the requirement to iOS 12 just to simplify our testing / development work.
But yeah, basically good news from the Distracted Pleco front - we've got nothing to do this summer but finish 4.0 - but desktop excitement will have to wait until 2019.