This is one of the most common things on twitter, people respond/reply to each other tweets all the time. Basically it goes like this:
If the original message says:
"Does anyone have any new twitter apps" and the tweet is coming from @GoogleSEOTools, then your reply would be:
"@GoogleSEOTools - I have some new apps for you to check out".
Basically when @GoogleSEOTools logs back into twitter (or any other twitter app) he would be able to look at your tweet under a different section.
If the original message says:
"Does anyone have any new twitter apps" and the tweet is coming from @GoogleSEOTools, then your reply would be:
"@GoogleSEOTools - I have some new apps for you to check out".
Basically when @GoogleSEOTools logs back into twitter (or any other twitter app) he would be able to look at your tweet under a different section.