First of all send your self an email with this in it as a link "email:send?attach=ur0:shell/db/app.db." without the quotes after this open this email on your vita and click the link then once again send yourself an email this time it should an an attachment , back on your pc now open the attachment in a sqlite database editor goto the tbl_uri table and add a new record as the following:
TitleID:The App your want to run(eg.NPXS10031)
flag:1(as pointed out by niszczycielnpc this allows you to use this link in the browser)
scheme:The call your want (eg.pkg)
leave the host path empty and save changes next send yourself an email with this as an attachment and rename it to "#0" without the quotes and put the subject as "ur0:shell/db/app.db" again without the quotes, open this on your vita click the attachment but DONT click ok then close the email app.
To test if it works send yourself and email with your link in for me that would be "pkg:" remember the colon on the end and your Done!
ToDo:
Video
Pictures
This does not work with the package installer it will open then close




