I don’t know specifics about the UK version, but most of those costs likely weren’t on the app proper. They did run a field test, for example.
For comparison, the German version cost millions, too. That included multi-language support, setting up help lines, security evaluation, load testing millions of concurrent users and, IIRC, connecting to quite a few of different hospital computer systems.
Add in time pressure, and costs go up. Germany did get a quality system, judging by what the spokesman for the Chaos Computer Club said (paraphrasing: ‘we have the unfamiliar problem that there is so little to complain about’. They never endorse stuff, so that’s about as endorsing as their statements can get)
It also includes the DPIA, which in itself can be an expensive process. There was a lot of concern/press in Ireland pre-release about the privacy implications of the app. It's hot on the heels of a "mandatory but not compulsory" national ID card fiasco that was determined to be unlawful by the privacy regulator last year: https://www.thejournal.ie/psc-no-legal-basis-4766822-Aug2019...
We ran a field test too. But again; I probably can’t talk about that much. Sorry. If you have more in depth technical questions I might be able to answer them.
For comparison, the German version cost millions, too. That included multi-language support, setting up help lines, security evaluation, load testing millions of concurrent users and, IIRC, connecting to quite a few of different hospital computer systems.
Add in time pressure, and costs go up. Germany did get a quality system, judging by what the spokesman for the Chaos Computer Club said (paraphrasing: ‘we have the unfamiliar problem that there is so little to complain about’. They never endorse stuff, so that’s about as endorsing as their statements can get)