Current smartphones are highly optimized for content consumption a.k.a doom scrolling. Nothing serious exists for programming. On top of that, a touch keyboard and hard to reach special characters make programming on a modern smartphone a big chore. I miss the old days of smartphones that had a hardware keyboard with tactile feedback. I used to code up and maintain a PHP based dynamic website circa 2007 with a Sony Ericsson K770i and upload through a J2ME based FTP client that also had the text editor in it. If I remember it correctly it was called MobyExplorer

I did, in Java 2ME for my Nokia. That was a completely different experience and much harder to get going. I did make a color 2D game though in about a week.

The TI-200 was much more accessible and fun, creating small little programs during or after class. Only once you wanted to go assembly did it become a chore again.

To summarize: not the same.

What's your favorite free programming environment for commonly used smartphones?