Currently, the iD Mobile network's website (https://my.idmobile.co.uk/) is down.
The front page loads, but there is a connection error to any of the other webpages.
iD Mobile is part of the Carphone Warehouse (or Dixons Carphone, to give them their proper name) and piggybacks on the Three network.
They do have some good packages, but can't quite challenge Three at the moment.
Hopefully, the website will be back up and running soon, as there must be a fair number of customers from other networks looking around this Friday afternoon to see what the best unlimited data plans are, now that Three and giffgaff are either increasing their price or restricting data use for their respective PAYG plans.
PAYG is not the best way to get unlimited data any more, apart from Vectone who currently offer unlimited everything for £10 a month - though you may want to try them out or read some reviews before committing to them.