I've never had much luck with Tapdancer, and I'm no fan of skuomorphic UI. Looks cool, works poorly.
Anyway, because of that earlier this year I added basic TZX/CDT support to PlayUEF, which is a Beeb tape player webapp. I really should have mentioned it at the time, but I got distracted?
You can run it locally, but it also works from my github instance:
https://pelrun.github.io/PlayUEF/PlayUEF.htmlIt'll work from your phone! It won't leave WAV's on your storage! It has a standard playback bar (seek to time positions!)
I have the main CDT blocks handled, but not *everything*, so let me know what images it chokes on and I'll have a look.
I actually wanted to have it automatically download CDTs from cpcwiki, but security settings stopped me. Poop.