Build a tool for manually classifying training data images
I would recommend building your own database-backed Web app, since you have proprietary data and few (only two?) classes. I would create tables for the images, users, and labels.

user: (id, name)
image: (id, url)
label: (user.id, image.id, time, class)

The label class can be an enum. If you don't want to let users rate the same image multiple times you can drop the time column, and set the first two ID columns as the compound primary key.

If you've never dealt with Web applications and databases it will seem complicated, but it is easy once you get the hang of it. Here is a tutorial. The benefit of this approach is persistence; you can turn off your computer and the start where you left off thanks to the database.

A simpler alternative is to collect all your data in one session using GUI components such as ipywidgets for jupyter, and writing the labels to a file. With this approach you do not get persistence.