Neyens is an independent app studio. How you remove your data depends on the app — each app's own deletion page has the exact steps.
On-device and private by design — there is no account. Deleting the app removes all of its data. Details: digitalquartermaster.com/deletion.html
Multiplayer scorekeeping — leave or end a game to stop sharing, delete the app to clear local data, or email a deletion request. Details: mygamecrew.com/deletion.html
Can't find what you need, or want to make a deletion request directly? Email kristofer@neyens.com.