EP Calipers is an app that allows you to use electronic calipers to make measurements on images of ECGs or EP recordings. See this post for more details.
EP Calipers is available for iPhone or iPad, Android devices, Mac, and Microsoft Windows™. As Microsoft does not have a desktop App Store [but see UPDATE], you can order using this secure link. The cost for the Windows version in the US is $4.99.
UPDATE: Microsoft is now accepted converted Win32 desktop apps for their App Store. I am in the process of converting the app for the store and it should be available soon. Stay tuned.
UPDATE 2: I am in the process of add angle calipers to EP Calipers, as well as features allowing assessment of Brugada ECGs. When this conversion is complete, further information will appear here.
EP Calipers for Windows
EP Calipers on iPad