You don't have to. All users can access applications in the Applications folder unless they were installed by another user via Drag and Drop or have been restricted in a managed account.
For the former just change the permissions on an inaccessible application:
1. Select the application. Press COMMAND-I to open the Get Info window. At the bottom is the pane for Ownership and Sharing.
2. The correct settings should be:
Owner=system with r/w privileges
Group=wheel with read-only privileges
Everyone is read-only
If the owner is a username then you need to change the permissions as follows.
3. Open the Terminal application in your Utilities folder. At the prompt enter:
sudo chown -R root:wheel
Put a space after "wheel" then drag the icon of the application into the Terminal window. Press RETURN. Enter your admin password when prompted. It will not be echoed. Press RETURN again.
If you have more than one application whose permissions need to be changed then select all of them and drag them into the Terminal window instead of just the one.
For the latter if the other user account is a Standard or Managed account, then you have to assign what applications that user can access via Parental Controls preferences or change the account to an admin account.