I may have a way to have the Epic Broswer avaliable on the iDevice, although it's not going to be an app in the outcome.
I would suggest making the Epic browser for the iDevice called Epic Proxy, and it can be installed by visiting one of your sites.
Visiting that site would install a Provisioning Profile, which in turn add an app that allows the proxy to be turned ON or OFF.
Because as of this moment, I don't believe there is an open source Chromium for iDevices.
So making a Provisioning profile that would contain the proxies would be excellent, and providing a simple ON/OFF app that would turn the proxy off/on
TLDR; No App Store - use Provisioning Profile
Until then, is it possible to enter the proxy into the Wifi Settings manually?