BBX BASIC V 4+

A few glitches

There's another implementation of BBC BASIC on the AppStore, which (unlike this one) is free and supports graphics. You might still want this one even so, because the user interface is less exotic and it lets you choose between writing your programs in the editor and doing it the old-fashioned—more interactive—way by typing line numbers. (For short programs I prefer that.) But there are a few glitches/bugs:
• the in-app HELP doesn't work: it doesn't do anything at all. Other sources of help on the language are available online, but it means the specific features of the app aren't properly documented. NB. For working with files it uses SAVE, LOAD, FILES, KILL; you can customize the foreground and background colours with SET FCLR <r>,<g>, and SET BCLR <r>,<g>,, each parameter being 0-255; to change the font use SET FONT <name>,<size>, e.g. SET FONT "Bedstead-Extended",12 for a teletext font (if you've got one installed); SET STORE saves your settings and SET RESTORE reverts to the defaults
• the random number generator is reseeded to the same value each time you run a program, whereas it should be a pseudo-random value; you need to include a call to RND(-ABS TIME)
• the app doesn't remember your LISTO setting when you reopen it
• most seriously, if you pull down in the editor (which is very easy to do by mistake, when you're e.g. scrolling to the top) it bins your edits and reverts to the last saved version. Very frustrating when it happens!!

None of those things make it unusable by any means, but a paid-for app ought to get them right. And there doesn't seem to be an obvious way to contact the developer about them (which is why I've gone into
detail here).