I did a quick and dirty review and teardown of these cheap digital AC panel meters that read voltage and current.
I got a blue one and a green one:-

The insides (I can't see any markings on the main chip):-

Pros:-
Bright clear display
Cheap (abut US$3.60)
Easy to mount
Can sense up to 100A (and up to 500V)
Cons:-
Doesn't show currents less than about 750mA
Current readings seem to be be low/inaccurate
Voltage readings are also a little hit and miss, only accurate to within about 2-3%.
For low currents they are probably pretty useless, but if the load is always over 1 amp, they may have a place.
I'm thinking that it may be possible to add a trimpot to calibrate the current measurement. (But I need to get something to accurately compare it against)
Video:-