Fail In London, Try Hong Kong
OK, so they haven't failed (yet)
Hong Kong has the minibus fleet which his highly flexible (red) and more regulated (green). There are loads of these buses all over HK and are used on both short (2 miles) and much longer (10+ miles) routes.
There is also the possibility of the fleets being more optimally managed. I often see many buses queued waiting for their next run, especially in places where routes are attractive: Mong Kok to Yuan Long or Mong Kok to Sai Kung.
The data from the application could inform waiting passengers of the wait time and capacity of next buses. One some routes the buses depart with a certain number of empty seats, others only depart when full.
Given that HK is much smaller than London, but has a similar number of people (7.5 million). Most journeys involve public transport 90%+, the fleets already exist, HK is covered with almost 100% coverage of 3G or 4G and there is often free WiFi, I think they're missing an opportunity.
More importantly, if they want to corner this market, Tencent is across the border in Shenzhen and they're probably already reading this and thinking about it.