Twitter Apps

I’m searching for a twitter app that does the following:

1. Allows me to search for some keywords.
2. Allows me to filter by users/keywords/location. (for example, I might want to receive no results from @abcd)
3. Keeps all the results in a list, and once I’ve read them I can delete them.
4. Updates in real time, or at least once every hour.
5. Allows me to reply from within the app.

Any recommendations?

Twithawk would be perfect if they wouldn’t clear the tweets list every 24 hours or so.

Also, it should allow me to filter by removing RT.