A while back, in the finals of my third year at the university of technology and in the midst of the pandemic, they decided all students must submit their answers "handwritten on a white A4 paper and then collected in a single pdf document".
I asked some of my peers if they knew how to do the second part (Grouping images into a pdf document) and to my surprise most of them didn't know how to.
After some research I found a handful of websites that does exactly that, shared my results with couple of my friends, they told me "It is not that easy".
So, I decided on making a small Telegram Bot, you send images to and it sends you back a PDF file as a joke.
Shared it with them and they liked it because it was so convenient to use.

which brings me to the time of writing the post (February 22, 2021)
The bot launched in June 19, 2020.
Throughout its lifetime, the bot served more than 200,000 users.
it's actively serving more than 60,000 students in Iraq.
Generating more than 16,000 PDF files a day.

Here's the bot t.me/SwiperPDFBot
And here's the channel linked to the bot t.me/SwiperTeam