GifGaf here... Cheapish and I've had no problems with them. They piggyback of O2.
I've got over £25 of credit by signing up a few other people via free sim cards. It's useful to have in case you need to call pricey non-geographic numbers.
I've got over £25 of credit by signing up a few other people via free sim cards. It's useful to have in case you need to call pricey non-geographic numbers.