Passknacker is a community that collects mountain passes in Europe. At the point of writing they had over 3.700 different passes. They allow you to download GPX files of all passes. You need to sign up, but it's free. Simply download the pass collection you are looking for.
This page focuses on Passknacker, but there are other great resources out there as well. For example Alpenrouten; go to “Download” and download the “GPX-Datei mit vollen Namen”.
Move the GPX file to your mobile device, you can also download it directly on your mobile. You can import this collection in the Kurviger App, via
Import choose Overlay (not Routing). Simply plan your route using the additional overlay information to visit the passes you want to visit.
Importing into Kurviger Web is very similar to the Kurviger App. Click on the
Import button. Select your previously downloaded GPX file (there are issues with the upload using Internet Explorer/Edge, we recommend Firefox or Chrome). Only select
Show GPX data as overlay, if you also select the routing option, the result won't work well, as you added too many points, without any reasonable order. Click the
Import button. The map is filled with your GPX data. You can use the imported points to plan your routes visiting all the different passes.