You can use nm(liux/mac) to find exported and imported functions/symbols, is it possible to find the non-exported symbols of a binary in a similar way? Are there command line tools to assist with this?
Primarily looking to do .apk/.ipa analysis.
You would need to ask the developers of those Android / iOS apps for the symbols. It's very unlikely that they've made their apps' symbols publicly available.
However, keep in mind that although symbols are helpful, they aren't required to reverse engineer an app.