There are several light meter apps for Android, but I can't speak for their accuracy (you need to google around and read some reviews).

The problem with the Android platform, is that there is a much larger variety in hardware than with Apple, so from what I've seen, the Android-based meter-apps seem to only support a small list of phones.

I used my iphone while in Tokyo, shooting with my Hasselblad, was noon and sunny and very hard and contrasty light.

End result was a lot of photos with contrasty light, but not one frame wasted due to fubar exposure.
Normally I use it to get an average exposure for a scene, or to check the stop-difference between the sky and ie. water (the meter shows EI-numbers as well, so calculating the difference in stops is a breeze).

I'm still struggling to understand my Minolta Spotmeter F, as I'm having issues trying to calculate the frigging aperture 2.5 stops faster than f13 for example. (how do you do that quickly anyway?)