Unit converter plus is a free Android Application with simple user interface, anyone can use it easily. We cover lots of Units in this app, we categories the units into Eight Major types, such as:
General, Mechanics, Computer, Electronics, Heat, Sound, Radiology, Ohm's Law Calculator and Other Units.

Detail Units and its sub units are as fallow:

Length:
Inches
Feet
Yards
Millimeters
Centimeters
Meters
Kilometers
Miles

Weight:
Ton (metric)
Kilogram
Hectogram
Gram
Milligram
Carat
Grain
Pound Avoirdupois

Volume:
cubic meter
cubic decimeter
cubic centimeter
liter
deciliter
centiliter
milliliter
fluid ounce
fluid ounce
cubic inch
cubic feet
cubic yard
gallon(UK)
gallon(US)
petroleum barrel
pint(UK)
fluid pint(US)
dry pint(US)

Temperature:
Celsius (°C)
Fahrenheit (°F)
Kelvin (K)
Reaumur
Newton
Rankine

Distance:
kilometer
meter
decimeter
centimeter
millimeter
mile
inch
foot
yard
nautical mile

Speed:
kilometer per hour
meter per second
miles per hour
knot
mac

Angle:
Degree °
grad
Angular mil
Minute of arc
Radian
Second of arc

Radiation:
coulomb/kilogram
millicoulomb/kilogram
roentgen
milliroentgen
parker
rep

Data Byte:
bit
nibble
byte
character
word
kilobyte
megabyte
gigabyte
terabyte
petabyte
exabyte

Area:
square kilometer
square meter
square decimeter
square centimeter
square millimeter
hectare
are
centiare
square mile
square inch
square yard
square foot
rood
acre
square nautical mile

Energy:
Joule
Kilojoule
Calorie
Kilocalorie
Watt-hour
Kilowatt-hour
British thermal unit
Therm americain
Foot-Pound

Thermal Conductivity
watt/meter/K
watt/centimeter/°C
kilowatt/meter/K
calorie (IT)/second/centimeter/°C
calorie (th)/second/centimeter/°C
Btu (IT) inch/second/foot²/°F
Btu (th) inch/second/foot²/°F

Radioactivity:
becquerel
kilobecquerel
megabecquerel
millibecquerel
curie
rutherford

Frequency:
microhertz
millihertz
hectohertz
hertz
kilohertz
megahertz
gigahertz
terahertz
petahertz
exahertz

Pressure:
pascal
millipascal
micropascal
kilopascal
Bar
Millibar
Pounds per square inch
kilopound per square inch
Atmosphere
torr

Time:
millennium
century
decade
year(common)
year(leap)
year(sidereal)
year(Julian)
year(tropical)
month
week
day
hour
minute
second
millisecond
microsecond
nanosecond

Power:
watt
kilowatt
megawatt
gigawatt
terawatt
deciwatt
centiwatt
milliwatt
microwatt
nanowatt
horsepower (metric)
horsepower (electric)
MBH
Btu (IT)/hour

Torque:
newton meter
newton centimeter
newton millimeter
kilonewton meter
dyne meter
dyne centimeter
dyne millimeter
ounce-force foot
pound-force foot

Density:
kilogram/cubic meter
kilogram/cubic centimeter
gram/cubic meter
gram/cubic centimeter
kilogram/liter
gram/liter
centigram/liter
milligram/liter
pound/gallon (US)
ounce/gallon (US)
grain/gallon (US)

Sound Level:
bel
decibel
neper

Capacitance:
farad
microfarad
nanofarad
picofarad

Inductance:
henry
kilohenry
millihenry
microhenry
nanohenry
picohenry

Resistance:
Ohm
Volt per ampere (V/A)
Milliohm
Microohm
Kiloohm
Megaohm

Number System:
binary
octal
decimal
hexadecimal

If you want to more units in this app, feel free to email us