CrowdCall, a free mobile app for iPhone and Android, allows you to create free conference or group calls with up to 20 people anywhere on earth. The app, from Socialdial Inc., calls for users to select the people they want to include in their conference from their contacts list, touch the call button, and begin. Instead of creating a dial-in number and PIN codes, CrowdCall calls everyone on the conference list when the user presses the call button. There’s no need for participants to have the app to participate. The only cost is a local call from the user to the CrowdCall service, which uses local minutes on phone plans.