Recently , Android marketplace became online . Now you can install Android app from your computer or laptop without using your phone . Read below post for further information .
Steps to Install App
Step 1 : Go to https://market.android.com/
Step 2: Search the app which you are going to install in your phone .I chose Wolfram Alpha.
Step 3: After searching the app , Choose either Paid version or free version .
Step 4: After you click Install, new pop up window will be opened . Here we have to sign in using our google account .
Note :We have to use same google account which we are using in our android phone .
Step 5: After Sign in through google account, It shows our Phone Model no .In my case its Samsung GT-I5510.
Step 6: Thats it , Android app will be installed on your phone without touching it .