URL Encoding of + sign?

Thanks for the awesome tool! It's very helpful in debugging REST services.

How exactly do I send over a + sign?
I tried:

GET ?email=user+tag@example.com

Result: the + doesn't get encoded, is interpreted as a space (as expected)

But also:

GET ?email=user%2Btag@example.com

Result: the % gets URL encoded resulting in user%252Btag@example.com which is treated as the literal 'user%2Btag@example.com'