Hey you want Answer your incoming call Hands Free by automatic then simple installs "Hands Free Auto Answer Call".
Hands Free tool have some more option are there.

1) Auto Call Answer : Set Duration to Answer your call or accept your call after 5 or 10 or 15 or 25 or 30 seconds, According Settings. and also option to Activate Loud Speaker Automatic Hands Free after call answer.

Caller ID Options:
* Enable/Disable Hands Free Accept incoming Calls.
* Caller Name Announcer with Theme Caller ID.
* Caller Announcer to announce Caller Name.
* Disable/Enable Unknown Calls Announcer.
* Call Duration window after ending incoming calls.
* different types of Caller ID Themes.

* This App Very use full for emergency in Car Driving or other busy work to accept call.