Here are the key steps for how to download apps from Google Play directly.
1. Set up the utility and save it.
2. Now get your device ID.
3. Search out for the apps you want/wish to download from Google Play.
4. Set its download location.
5. Have fun in downloading the app.
Note that if you did any mistake while in the settings, especially while giving your email address (of GMail, Yahoo, Hotmail, Orkut) its password and the device ID, the utility you make will through error while logging in and you can't download the app. If, then double check your setting and correct the errors.