We have the option of adding App Collaborators. This gives you the option to invite other accounts on Pushy to access and modify an app of yours.
Have the person you want to grant access to sign up for their own Pushy account:
https://dashboard.pushy.me/register
You can then add them as a collaborator as follows:
1) Go to the Apps page
2) Click your app
3) Click App Settings
4) Click the icon of a person (App Collaborators)
5) Enter your colleagues' Pushy account e-mails
6) Click Add Collaborator
Note: Billing for the app will always be tied to the master account which owns the app.