Parse is cool, but the pricing is a deal breaker for me. According to their plans page (https://www.parse.com/plans), I'd need a pro account to enable multi-app push. Pay Pad is three apps actually so the combination of UrbanAirship and Webscript.io end up being a very cheap solution if I wanted to ditch my current implementation on Heroku.

Although I suppose you could get around the multi-push-certificate restriction with multiple Parse accounts. If you had two iOS apps, then you'd be making two web requests out to Parse. Although I do this now with UrbanAirship so there would not really be a difference. Interesting.