Usability
Interface 
User-friendliness/complexity of the tool´s interface
Straightforward.
Time efficiency Time needed for mastering the „how-to“ of the tool and a production of a task
Medium.
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?
Very high. Pingo only collects user data and cookies, amongst which IP addresses and browser data, for technical security and web server operations and not other purposes such as marketing or advertising. Moreover, user data is deleted after 30 days. Pingo does not share data with third parties or display advertisement. Its privacy policy could nonetheless elaborate more on security measures. Pingo states compliance with the GDPR. See more here.
Saving work for future use Possiblity to save your or others´ work for reuse/reproduction
Yes, it allows visualising results and saving polls with an account.
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)
Medium, users can create polls for diverse purposes.