I was looking for something like the python application LabelImg but on the iPad so that I could use my finger and hopefully Apple Pencil. Not only is this exactly what I was looking for (including pencil support), but it seems super well designed, too. I have no idea why you would buy one of the other apps with their $3-$10/month subscriptions. If all you need is to draw boxes and name them, this is the app for you. Thank you, Mr. Rodriguez Junquera!
One suggestion, if I may, to make this already awesome app even better: could you add the ability to read from the filesystem (like in the Files app)? If so, I could airdrop pictures (and xml files? Would that be possible?) from my Mac that I already have started labeling and open them up in Lince. That would be perfect!