"an webapp" or "a webapp"

Just for me:
Is it pronounced “a webapp” because of the “w”? Or “an webapp” because it’s an app and web is a property of it?


and: is “webapp” right or “web app”?

I’m no English expert but I’ve always seen it as “a webapp”. “An app” is correct too, but I’m pretty sure that “an webapp” is not correct.

Usually “an” precedes something that doesn’t start with an enunciated consonant
So you get “An Apple” and “A wish”
However you also end up with “an hour” because the “h” is not enunciated
Or “an X-Files episode” because the X is pronounced like a vowel sound

Chicago Manual of Style, 16th edi­tion, University of Chicago Press, (5.72) says that the choice depends on the sound of the word it pre­cedes. “A” comes before words with a con­so­nant sound, no mat­ter how the word is spelled. Further, an “an” comes before words with a vowel sound.

Chicago Manual of Style is a pretty good arbiter of these things.

Shouldn’t it be a “Web app”? Web should be capitalised since it’s a proper noun (or a shortened version of one: World Wide Web).