via http://www.aep-emu.de/

Marat Fayzullin has ported his (free) Spectrum emulator Speccy to the Android platform: Speccy for Android

Quote:
New in 1.7.12:
  • Fixed Native/Java communications during display updates.
  • Made display updates faster and smoother.
  • Fixed SEARCH button to continue working after screen rotation.
  • Made fast-forwarding even faster.