An OPO (compiled OPL) interpreter written in Lua and Swift, based on the Psion Series 5 era format (ie ER5, prior to the Quartz 6.x changes). It lets you run Psion 5 programs written in OPL on any iOS device, subject to the limitations described below.
↫ OpoLua GitHub page
If you’re pining for that Psion Series 5, but don’t want to deal with the hassle of owning and maintaining a real one – here’s a solution if you’re an iOS users. Incredibly neat, but with one limitation: only pure OPL programs work. Any program that also has native ARM code will not work.