It would be better that you were able to get permission from your soon-to-be former employer, but it seems like this is something that they or you are not willi

It would be better that you were able to get permission from your soon-to-be former employer, but it seems like this is something that they or you are not willing to discuss. You are not asserting any ownership rights over the apps; you are simply stating the facts. As these are (presumably) App Store downloadable - there is no case that these are proprietary. The ideal situation is that you leave on good terms with your soon-to-be former company but I think it is perfectly ethical to state which apps you worked on, as long as you clarify that you only did part of the app (assuming you did). It's not like you are stealing their entire Git repository. As for legal, think of yourself as a producer or director. What company would have the right mind to sue someone for claiming that they worked on a film. So this is not legal advice but logical: it should be fine to tell people online what you worked on and be sure to include a backlink. The bigger problem for you in my mind is them asserting ownership of what apps you may have started while still working their, on your own time.