I've been pretty happy with SoFi. I like that they support multi factor authentication with TOTPs. I haven't had to deal with their customer service yet.
Their Android app is god awful though if that matters to you. Also they send me a ton of spam but Gmail takes care of it so for me that's a minor issue.
I suggest having your students install IntelliJ IDEA and using Java. A full blown IDE might be much but I can't think of an easier way to install a JDK and an editor suited for it.