Most of the apps that Agant has produced appear to be aggressively priced (seems most are around £9.99, the most recent at £24.49). Though, they do target a rather niche market. I'm very curious as to whether the apps did not sell well or simply did not cover the cost of operation. Whatever the case, now that Dave is the sole employee the revenue of the existing apps will not hurt.
Finally, I'm also wondering if Dave ended this adventure simply because he was not enjoying it, or if Agant was spiraling into debt. I can't really tell from this post. He does mention that making it in the App Store is difficult, but that some of the apps were created for clients (some being partners). I can't imagine that there wasn't enough good work out there for a talented team of proven developers+designers.