Hi.
I have a printer with a sheet feeding scanner (I think that’s the name in english). As many of this scanners, it only scans one side of every page, so for scan a two sided document, you scan one side of the pages, and then scan the other side. You are left with Two PDF files, one with the even pages in one PDF in regular order, and one PDF with the even pages in inverse order.
To fix this I always used webpages that merge those PDF for you, but I’m always a bit concerned about the privacy of those sites… Yesterday occured to me that this is a nice APP idea for Nextcloud.
My current idea is that the app should have an option to “upload” as many PDF files as you want, and options of how to merge them. Maybe you want to merge two or more PDFs secuentially, or even the opposite and separate each page in individual PDF files. I think this has a lot of potential to be exploted, and a lot of many use cases.
I would like to see your opinions and ideas for this, maybe I’m a bit too enthusiastic about this and it’s blinding me 
I’m a Junior web developer and if this gets traction and some people want to help I want to be part of the development team for the APP. This is not just “I want you to make me an APP”.
Thanks!