The two SEEM to be connected but I have observations in one that I don’t see in the other (both ways). They don’t seem to SYNC very well. It’s frustrating. I’d like to add pics to various observations that are in iNaturist but would have to add them to my computer from my phone because those observations aren’t showing up in Seek. In addition, I have some observations in Seek that I can’t get up to iNaturist (there’s no way to “PUSH” an observation from one to the other).
The two apps were never intended to sync in both directions. Seek is an ID tool suitable for all audiences including children. Recently the capability was added to push Seek observations to iNaturalist for those who have/want iNaturalist accounts and are old enough to have one. I’m guessing there would be no intent to allow pushes in the other direction, otherwise there would be little point in having two different apps.