--Google Contacts for the phone numbers on back of cards.
--Spreadsheet for card/date of application/date of closure/signup bonus + terms/spending left for bonus/notes/opening credit limit/current credit limit/type of approval (automagic vs recon)/credit bureau pulled(if any)
--KeePass for all CC numbers, AUs, expirations, security codes (works wonderfully on comp and use the android version as well)
--Mint for all random stuff like annual fees etc
--Business card holder for physicall CCs