coding, (retro) demoscene, emulation, ...
after read this review i buy this great app, but ... i cnt play any of .sqt spectrum files :(
For Spectrum the common music format is AY afaik... Perhaps you can find the music you want to hear in this format or convert them using a third party tool ?
maybe ist not zx format but i search for stormlord theme music in modland and i find it in Spectrum SQ Tracker category. All files with .sqt dnt play(i only download it from modland not convert by myself)