That said, I had no problem with their API. They had an easy web checkout link that could be generated that worked fine in an Android WebView for my first implementation. Later at AngelHack SV I used their PHP API to generate invoices for specific prices for goods dynamically and was then still able to send people to their site to finish checkout and get redirected when it completed.
Didn't really see any missing documentation and their site worked fine, responding quite quickly when money was sent to the barcode it showed or the link that could start a wallet app on Android, and their PHP sample code worked trivially. Who knows, maybe they've improved the docs and samples since you used it, though. Or you were trying to hack bitcore, which is a completely different level of difficulty.
We just this past week launched our new REST API, which should be significantly better than our old API: http://blog.bitpay.com/2014/09/18/announcing-the-new-bitpay-... – we spent a long time thinking very carefully about making the developer experience as smooth as possible, but I'm sure there are things we can be doing better. If you've any ideas on how we can improve it, please let me know.
http://blog.bitpay.com/2014/07/01/bitauth-for-decentralized-...
Regarding your AngelHack prize... the same thing happened to me. I'd be more skeptical of AngelHack than Bitpay, a well-funded global company, though: http://www.businessinsider.com/greg-gopman-angelhack-lawsuit...
It's not the first time I've heard of AngelHack not following through.
Hah... that library was awesome to work on. Ended up reimplementing the signature algorithm before getting a library that lets us use golang's built in ecdsa libs. Not clever!
Love BitAuth. It's super easy to use and works brilliantly.
I'm using their old version, but the errors I get are from the new version. Their library for the language I use is not yet updated. The new docs seem to be better, but I lost faith in them as a developer.
Always feel free to shoot me an email at eric@bitpay.com.