You might also want to try the freely accessible Chemicalize.org that allows you to get the predicted logP value for any query compound along with several other useful information on their physicochemical properties (you can select the "All calculations" option to activate the detailed mode that show several properties like atomic charge, isomeric form, etc.). However, this tool does not provide any potency information.
http://www.chemicalize.org/
Additionally, you might want to check out ChEMBL that provides you with detailed potency information (putative targets) along with its corresponding properties (the typical rule of 5 properties like hydrogen bond donor and acceptor, molecular weight, etc).