Tablets/iPad only, phones are not supported. 80-85% of what I make/play on Snap! I have used my iPad. I’m using it right now. Tablet also works pretty well.
I believe no phones will work solei because of the UI/IDE. The whole, including the community site, has no phone UI built. I would suggest iPads and Laptops or alike.
In 1st world countries you'd be right. In 3rd world areas there is no choice, and those students can be very determined & creative on phones. But I agree with @joecooldoo : the Snap UI would need a mod to be usable there e.g. one or two panels at a time (palette, scripting, stage + corral) instead of all three. There may be other subtler issues with Snap + mobile.
I understand, it will be hard to do, but possible. I wouldn’t know how to make this mod, but we can start a collaboration to make Snap! phone comparable.
It is possible to code in Snap! using an Android; although, it can be a bit difficult trying to maneuver on a small screen. But it is possible! I was able to create two projects/games on an android. Not all browsers work well, but Chrome seems to work great!
Yeah, I have used snap on an android tablet. My experience s that it is incredibly hard to tap and hold for right-click, well, at least compared to my ipad.