I completed the “It’s all about Soul” achievement on the PC, and got credit in Steam there for it. However, I can’t find any way to get credit on mobile (Android). I tried visiting the Soulforge, restarting the game and crafting something.
One the other hand, the Curse Be Gone achievement worked for both platforms. I completed it on mobile, and when I logged in on PC, it was credited immediately. That’s working at least.