twizyx is just a OVMS in disguise.
They bought the OVMS Box like everyone else for 99€ at Fasstech and put their SIMcard in it and a sticker on it.
If you "buy" from them they send you the box and tune your Twizy via SMS or GPRS commands.
Then they want their box back, otherwise you lose a deposit you made extra to what you pay for the 5 Minutes of time and the SMS they spend for the worth of your money.(Deposit is exactly what they payed for the OVMS)
So its a big old scam. Thier business relies on the work of others(open source) and the lack of knowledge for thier customers.
These pay plenty for something you can have for free if you know (someone with a ) OVMS or even a PowerBox.
You can archive that tuning even with a simple ODBII dongle and the new android software.
Let them scam someone else.