How to choose a team for transferable skills?

I am not sure if expertise in a certain set of tools should be considered a transferable skill given that new tools keep popping up all the time in the software world and there's a lot of variation in toolset from one company to another. There's a reason big tech companies focus on problem solving and behavioral traits during interviews and not on the technologies you've worked with. For a software engineer, some examples of transferable skills are problem solving, good communication, responding well to feedback, ability to break down a problem into simpler tasks and quick learning.

For an entry level job, I'd suggest keeping an open mind and exploring different areas. Apply to as many jobs as you can , talk to recruiters and hiring managers and see what interests you. If you like mobile development , by all means go for it. But I am sure for an entry-level job they won't expect you to be an expert in it. So instead of waiting around to gain expertise, keep giving interviews. That way you'd get a sense of what is expected of you and you'll get better at interviewing.

Best of luck!