1.

Whiznook

2.

Wonder Workshop 2012

3.

Worddio: Vocabualry builder

4.

WorkDone Inc.

5.

Wundr AI

6.

Xembly

7.

XOR N/A

8.

XOR.ai

9.

Yomi.ai

10.

Yoodli

11.

Zeta Learning