I can totally relate. I took a very long break from mobile app development and find it pretty hard to get back into it mostly because of the UI. I'm also professionally dwelling more in the back end for the last couple of years, mainly writing web services. So yeah those skills definitely get rusty over time.
Funny that you also mention social apps that are getting less suitable for phones. A couple years ago I teamed up with a designer and we started work on a social app / platform. We tried to target mobile devices first and we desperately tried to cram our ideas into that way to small screen real estate. I was very frustrated working on those mobile app UI prototypes, and we faced several hard problems we could not really answer thinking in terms of mobile app UI. It was really limiting. And it also caused a ton of miscommunication between the designer and me.
After a longer break we began revisiting the concept, but I insisted on targeting desktop browsers first. It was completely eye opening for the both of us. We finally got to a point where we could freely express our ideas and discover suitable interaction ways. And we started feeling like: yeah, that's it.
We're taking it from there now, and treat the mobile version as an after thought. In our case I believe that UI enhancements for accessibility will give us some ideas and answers how to handle the smaller mobile phone screen.
If we're lucky and this whole thing turns out to be something, we may end up consulting Android and iOS specialists for fixing our mobile UI writer's block 😆
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.