ISO Tool v1.85 is released. ISO Tool is a handy homebrew application that lets you manage and backup your UMD's straight from your PSP. ISO Tool completes by Japanese Developer Takka.

ISO Tool v1.85 Changelog:
[BUG] 5.03GEN-C in the unstable patch was fixed Prometheus
[NEW] 5.03 GEN-C and in the implementation of switching Prometheus3 (5.03Prometheus3-v4 requires prior installation)

Download: ISO Tool v1.85
Source: Here