The PSM Development Assistent App is the only gateway to native Vita homebrew, exploited by @yifan_lu. Sony knows that, so they posted a new update on the PSM website, alerting users that a "software issue" was found in the app and kindly asking you to stop using and delete the PSM Dev App. If you don't do it, they will nuke your Dev App by forcing you to update to the newly released firmware 3.52.
Dear PlayStation Mobile content developer
A software issue was found in PSM Development Assistant/ PSM Development Assistant for Unity applications.
For those developers using PSM Development Assistant/ PSM Development Assistant for Unity, we kindly ask you to stop using the application and delete it from your PlayStation®Vita (PS Vita).
Please be aware that PS Vita system software update 3.52, scheduled to be released on June 24, will revoke the applications, and users will no longer be able to use it.
We appreciate your understanding and cooperation.
As scheduled, content updates are accepted until July 15, 2015.
I am happy to delete my Dev App, but only because Sony asked me kindly
Source: Yufi hacker dude's twitter, PSM Website
Dear PlayStation Mobile content developer
A software issue was found in PSM Development Assistant/ PSM Development Assistant for Unity applications.
For those developers using PSM Development Assistant/ PSM Development Assistant for Unity, we kindly ask you to stop using the application and delete it from your PlayStation®Vita (PS Vita).
Please be aware that PS Vita system software update 3.52, scheduled to be released on June 24, will revoke the applications, and users will no longer be able to use it.
We appreciate your understanding and cooperation.
As scheduled, content updates are accepted until July 15, 2015.
I am happy to delete my Dev App, but only because Sony asked me kindly
Source: Yufi hacker dude's twitter, PSM Website