EXE Radar Pro gives you full control on every single application that is installed\executed in the system and is more for advanced users. With EXE Radar Pro you can allow or block a specific process by matching process, parent process, signer, sha hash, etc. Here is a screenshot of the "Rule Builder":
OSArmor is for beginner users (but also for experts) with pre-built rules (30 at the moment) to block suspicious processes behaviors and that requires 0 configuration. It adds an additional (solid) layer of defense to your system. It was built to be installed in any PC without requiring user intervention and at the same time being able to prevent malware and ransomware infections. Here is a video of OSArmor in action:
He's probably busy with OSArmor, and some other business focused products right now. I think ERP doesn't make much money, the lifetime license is cheap and the free beta version(old one) was better than the (old)stable version. He's likely to focus more on business products which would make more money on subscription basis or such.
ERP is a niche software mostly known only by security forums members, OSA almost negates the use of ERP and since it requires far less user's inputs, it has more chances to be purchased than ERP.
The few reviews sites that knows about OSA already gave it better marks than ERP.