What browser is "vp-iphone" & "vp-ipad"?

We have a public API gateway to generate images.

Today I looked into the access logs and found a lot of API requests with User-Agents like:

• vp-iphone 6.121.0 sysVer 17.4.1-iOS
• vp-ipad 6.120.0 sysVer 17.4.1-iPadOS
• vp-android-smartphone 6.14.0

I have never seen User-Agents like this, and also have no clue what it could be.

One thought was that it could be some browsers from platforms like Facebook, Instagram and so on.

Also Googling for these User-Agents it did not give me the required information.

The IP addresses and their ISPs & regions totally differ.

Do you have any idea what this could be?

figured it out. It is the browser of the following app: veepee.de