Check out the Teenage Engineering Pocket Operators [0], so much fun to play with. I enjoy messing around with chiptunes on my PO-20 Arcade far more than I ever did in software.

The PO-12 [1] and PO-32 [2] (if you can find one) are the two drum machines in that line up.

[0] https://teenage.engineering/products/po

[1] https://www.youtube.com/watch?v=lzEvGGINE20 (this guy has videos for most of the PO series)

[2] https://www.youtube.com/watch?v=LMk8x9fsUQE

This is a browser-based drum machine with two TB-303-like units:

http://errozero.co.uk/acid-machine/

Complete with HN discussion:

https://news.ycombinator.com/item?id=13004621

Adding to the suggestions here, there's another benefit to playing with hardware.

If they start plugging in basic effects pedals, they'll learn about signal flow and signal chains that are relevant to all styles.

There's no fundamental difference between a microphone, a guitar or a drum machine plugging in to a delay pedal. Learning the basics of EQ (bass, mid, low) gets them on the path to studio mastering if they're interested in that side later. If they decide they don't like the creative side, they have the basics to learn live sound tech or sound engineering.

Good luck and have fun :)

How about one in the browser? There are a lot out there, this is just the first one that came up in Google.

http://www.html5drummachine.com/

Try Figure (originally by Propellerhead). It's not strictly a drum machine but it's fun to explore both from a musical and an user-interface aspect. Available for iOS and Windows.

I played with this one a bit and enjoyed it, as a novice: https://play.google.com/store/apps/details?id=com.mikrosonic... I also got G-Stomper during an Amazon sale although I haven't really played with it at all.

If you search the app store for "808" you'll find a lot of apps. The benefit is the original "real" 808 was relatively simple to use.

Caustic is great, a full DAW, cheap iOS, Android, windows (free), macos(free).

cheap hardware (you'll probably want velocity sensitive pads) Teenage Eng Rhythm, Korg KR mini and Volca Beats, the Alesis sr 16/18, Akai makes seemingly dozens of beat makers/sequencer/samplers, others from Arturia, boss, the Roland tr09 recreation, etc.

Also DAW builtins: Ableton live DM's, garage band/Logic Pro drummers, I'm pretty sure FL studio, cubase, bitwig, reaper all have something similar