Motability Go Charge app, I’ve used it a few times note however the price shown in the app may not be what you are charged. You may be charged less but not more.
I spoke to the app support at the time, they advised that the price shown will be the most you will be charged (since the app last synchronise with servers) therefore the CPO’s may have lowered the price or have an offer running at that time).
Hope that helps.