RE: Automate your Twitter presence with your own Twitterbot

You can use a Tweet Search in your bot's Twitter properties to process and reply or retweet tweets.
The Tweet Search uses Twitter's search API which has many options such as from:user to filter tweets.

See,
https://dev.twitter.com/rest/public/search

Replying to all tweets for an account may be considered spam will most likely result in having your bot suspended.

It is possible to reply to tweets that contain a set of keywords,

http://www.botlibre.com/forum-post?id=25560

You can also retweet tweets that contain a set of keywords,

http://www.botlibre.com/forum-post?id=13218