When a new giffgaff SIM is put in an iPhone, a text is automatically sent to that phone with the internet settings for iPhone. The same text is sent if you text SETTINGS to 2020 on an iPhone. This text links you to a configuration profile that sets up your iPhone for giffgaff internet. However, the profile linked to in the text is Unsigned, meaning that some apps such as YouTube, SkyGo, Veetle etc may well not work because they can't connect to the profile. The problem has also been noted in Whatsapp.
Change the link provided in the text to a link to a Signed internet configuration profile. This will abolish (hopefully) the streaming problems and as a bonus, the settings are more likely to stick when updating the phone if it is a signed profile. I have uploaded an example signed profile to my DropBox (courtesy of UnlockIT) which could be used in the text instead: http://db.tt/OZtY9gHQ
This idea should be easy to implement. All that needs to be done is for giffgaff to change the standard settings text for iPhones to include a link to a signed profile like my example above and that's it!
Please give kudos if you think this is a good idea - it will help it to be considered by giffgaff.