PSM+ allows you to access PSM and PSM Unity (coming soon) without a license from Sony. This means you can develop and test with the PSM SDK and PSM for Unity without a publisher license–even after Sony shuts down developer access. Additionally, it allows for hacks such as Rejuvenate to work on any device with PSM DevAssistant installed for unrestricted native homebrew.
You must be running firmware 3.51 or lower and have PSM DevAssistant installed on your PS Vita.
PSM+ is compatible with the PSM Unity Assistant app, but the rejuvenate hack has not been ported to this yet. You should be able to try PSM+ if you have the PSM App for unity, though, in order to confirm you can run PSM apps with it.
How to use PSM+
PSM+ works in two steps.
In the first step, you receive a special license by email that needs to be installed on your Vita , + matching files for your computer.
The second step is something you need to do on a daily basis: you need to update your license to prevent it from expiring. This is also done through an email sent by our servers.