Usability
Interface 
User-friendliness/complexity of the tool´s interface
Simple, user-friendly.
Time efficiency Time needed for mastering the „how-to“ of the tool and a production of a task
High.
Interface language(s) The number of languages in which the tool is currently available/adaptable to
English.
Respect for privacy Does the tool require registration? Who can see my data? Can I remain anonymous?
High (?). Pepelt does not contain a privacy policy, so this is difficult to assess. However, the website does not seem to gather cookies or display any advertisements. Pepelt is a not-for-profit platform set up entirely for educational purposes, so it should be respectful of user privacy.
Saving work for future use Possiblity to save your or others´ work for reuse/reproduction
No.
Tailorability (If so, how?) Possibility of the tool to be used for a range of different activities (e.g. to what extent you can organize a project assignment with a central activity based on this tool)
Not much; users can choose from the different picture books for use.