Yes, the Uber app (best known for car/taxi/minicab journeys) also retails GB rail tickets, coach tickets and Eurostar tickets.
They are currently advertising VERY heavily across the rail network (well London terminals, certainly), and offering a 10 per cent credit rebate on rail tickets till at least 29 February.
In the recent past both Amazon and Tesco have sold Uber vouchers at 15% discount, so combined with the 10% credit rebate, it adds up to a VERY attractive saving on the cost of rail travel.
I'm no fan of Uber as a company but I'm more than happy to exploit their current offer to the max.
Before the Uber offer came along I also bought LNER vouchers to gain cashback via Airtime Rewards.