That's totally a big area, yes. And if it's what excites Chris, then he should totally go for it. But it isn't my first recommendation, because most mobile apps are written in Objective C or Java, while Chris has learned Python. There's a fairly large amount of new stuff that one has to learn to transition from Python to a statically typed language, so it's not the most efficient path to a working app.

(It doesn't feel that different if you have been programming for a while, especially if you learned a statically-typed language first, but you've probably forgotten about having to learn about covariance/contravariance/invariance, or about memory allocation, or about type-casting).