Thanks to feedback from you, I have released version 184.108.40.206 of Compression Estimator. This is really a minor release.
I was filtering databases in the Database drop-down list based on compatability level. this is not necessary, since even databases in 9.0 compatability level can take advantage of compression.
So instead, when I list available SQL Servers, or you enter a Server name, I validate that it is at least a SQL Server 2008 or later version (compression was introducted in SQL 2008).
Thanks again for the feedback.
Till next time...