Resolve App by Dragon Forged Software is an iPhone front-end for the popular bug-tracking service LighthouseApp. As such, it requires that you have a LighthouseApp account in order to use it, but once you do, it gives you quick. convenient access to all your issues, right on your iPhone.
Resolve App includes real-time push notifications for ticket updates, ticket attachments via iCloud, custom ticket states, ticket and milestone project sorting, tag, milestone, and priority editing, and more. It supposed multiple projects, and you can view open, closed, invalid, and hold tickets, and all open and archived projects. There's even a built in browser and support for Markdown.
I bought it and played around with it a little using a demo account they were kind enough to provide me. I'm not a developer, so I lack sufficient foundation to judge the merits of LighthouseApp, but developers and designers I know have spoken highly of it. Resolve App does a good job of taking what looks to be a fairly dense, dynamic, and serious information set and making it usable on mobile.
If you're a LighthouseApp users and you want to take your support tickets with you on the go, give Resolve App a look and let me know what you think.