Letters, a few at a time
A new alphabet is what stops most people before they start. Letters teaches Cyrillic, Greek, kana and the rest in small sets, with a bar under each one showing how well you know it.

If you're learning Ukrainian, Russian, Greek, Bulgarian, Japanese or Korean, there's a wall in front of everything else: you can't read any of it yet. The usual answer is to hand you the whole alphabet on one screen and wish you luck.
What changed
There's a section called Letters, and it teaches them a few at a time.
- A small set — five or six — rather than thirty-three at once.
- Four ways to practice each: seeing it, hearing it, matching it to how it's read, and picking it out among the ones that look like it.
- A bar under each letter for how well you know that one, so you can see the three that are actually holding you up.
They're on the chalkboard too, printed rather than handwritten, because the printed shape is the one you need to be able to read.
It doesn't block anything
Letters is somewhere to go, not a gate. You can have a conversation on your first day without opening it — you'll be given the line to say and what it means — and come back to the alphabet when you feel like it. Plenty of people learn the letters by meeting them.