Android: How to create icons for all Resolution (LDPI,MDPI etc)

The General formula is :

LDPI = MDPI X 0.75
MDPI = MDPI
TVDPI = MDPI X 1.33
HDPI = MDPI X 1.5
XHDPI = MDPI X 2
XXHDPI = MDPI X 3
XXXHDPI = MDPI X4

instead of make all version we can make the larger one and by using image resizer software we can resize the image or icon for al resolution :

Download From Here :
You can download from here ,and its very easy to use just drag n drop your image and define the resolution by drop down ,it will automatically create folders in the same location where the current file is located .
LINK

and then 

Android Application Splash screen size

Hi!

How are you?... today I'll tell you  about different screen resolutions for android app design
















Following are the sizes for Mobile device:

• XHDPI: 640X480px
• HDPI : 640X480px
• MDPI : 470X320px
• LDPI : 426X320px

Following are the sizes for Tablet device:

LDPI

     Portrait : 200X320px

     Landscape :320X200px

MDPI

    Portrait 320X280px

    Landscape : 480X320px

HDPI

   Portrait :480X800px

   Landscape : 800X480px

XHDPI

  Portrait : 720X1280px

  Lamdscape : 1280X720px

Android Launcher Icon Design Guidelines

LDPI should be 36 x 36.

MDPI should be 48 x 48.

TVDPI should be 64 x 64.

HDPI should be 72 x 72.

XHDPI should be 96 x 96.

XXHDPI should be 144 x 144.

XXXHDPI should be 192 x 192.

Basic Formula :

Basically, all of the other icons should be in proportion to the 'baseline' icon

MDPI at 48 x 48.

LDPI is MDPI x 0.75.

HDPI is MDPI x 1.5.

TVDPI is MDPI x 1.33.

XHDPI is MDPI x 2.

XXHDPI is MDPI x 3.

XXXHDPI is MDPI x 4.

example:

so lets take an image with about the size of 100X100:

for mdpi it should be 100X100
for ldpi it should be 75X75
for hdpi it should be 150X150
for xhdpi it should be 200X200
for xxhdpi it should be 300X300
for xxxhdpi it should be 400X400

For more Details visit on official site of android :Here