responsive

Short definition from Wiktionary

Adjective

1. 1
   Answering, replying or responding
2. 2
   Able to receive and respond to external stimuli.
3. 3
   Using antiphons; antiphonal.
4. 4
   Susceptible to the feelings of others.
5. 5
   Automatically resizing and repositioning elements to fit the available space.
6. 6
   Suited to something else; correspondent.
7. 7
   Responsible.