Sorry for the delay in answering. Thank you all for your suggestions.
With Storeman I could install only Advanced Camera 0.9.0 but not 0.9.5.
So I used (despite of the warnings above) rpm --force. Fahrplan survived…
Anyway I also tried various orders of deleting and installing of those two apps.
Fahrplan works fine, but Advanced Camera only woks with the front camera. (See e.g. [Release notes] Verla 4.2.0 - #226 by enrish).
Thanks again, best regards, Uwe.