Bouygues Prepaid Card XL
 

So as described here:

http://prepaid-data-sim-card.wikia.com/wiki/France

You can get the 2 Euro package, use up the 500 MB and recharge 2 Euro at a time for up to 2 GB of 4G data over 8 days.

Has anyone confirmed whether tethering is allowed?

What about the starter kit price for a nano SIM?

If you can't use foreign credit cards for the recharges, how do you recharge online, use top-up voucher codes?

https://www.bouyguestelecom.fr/stati...e_Prepayee.pdf

no information here

maybe here ? https://www.bouyguestelecom.fr/stati...De_Service.pdf

bouyges xl card
 

This is a great value card, and yes you can use it to tether your phone or ipad to - it even gives you an allowance to make overseas calls to home. If you have an 02 contract you can use the data allowance to use tu-go and call and receive calls from your allowance on your normal UK number.
However, does anyone know if I can top it up online before I arrive in France?