A license will work only on a single computer at the same time, so if you want to activate it for the first time or you want to use the license on another computer you will need to do the following steps:
Open the tool you want to activate the license for, after you open it you should see a windows like this:
Copy the GUID from the tool and go to: http://www.igramtool.com/accounts/tools/. You should see a table with all your licenses, to change the GUID for one just click on the Update GUID, paste the GUID copied from the app and submit the new information.
Now you can enter the username and password from our website on the app to log in and start using the tools you have an active license for.