Species identification

Comprehensive open nature guides:
Bayer agricultural determiner: www.apps.agrar.bayer.de 
LakeExplorer: www.lakeexplorer.org 
BeachExplorer: www.beachexplorer.org 

Butterflies: 
Butterfly Monitoring: www.tagfalter-monitoring.de

Amphibians: 
Amphibians Guide: www.whose-tadpole.net/

Trees: 
Baumkunde.de (Tree Identification and Knowledge Platform): www.baumkunde.de/

Insects: 
Kerbtier.de (Beetle fauna of Germany):  https://www.kerbtier.de/enindex.html
NABU Insektensommer (Discover, Identify and Report Insects): www.nabu.de/tiere-und-pflanzen/aktionen-und-projekte/insektensommer/mitmachen/30048.html 
Picture Insect: www.pictureinsect.com 
BienABest: www.bienabest.de/bienabest 
Wildbienen ID (Identifying wild bees): www.bienabest.de/news/detail?tx_news_pi1%5Baction%5D=detail&tx_news_pi1%5Bcontroller%5D=News&tx_news_pi1%5Bnews%5D=5448&cHash=5165aa30402ade36f6791d70253ed919 

Snails and mussels: 
Schnecken checken (Snail identification): www.schneckenchecken.ch/

Birds: 
NABU Vogelwelt (Discover, Identify and Report Birds): www.nabu.de/natur-und-landschaft/natur-erleben/spiele-apps-klingeltoene/vogelwelt.html 
Vogelstimmen ID - iOS (Bird Sounds Identifier): www.apps.apple.com/de/app/vogelstimmen-id-rufe-gesänge/id554108575 
Merlin Bird ID -Android: https://play.google.com/store/apps/details?id=com.labs.merlinbirdid.app&hl=en&gl=US

Plants:  
Floraweb: www.floraweb.de
Flora Incognita: www.floraincognita.com
Plant Net: www.plantnet.org/en/ 
Pl@nt Net: www.identify.plantnet.org
iGräser (Identifying of the most common grass species in Switzerland): www.zhaw.ch/de/lsfm/dienstleistung/institut-fuer-umwelt-und-natuerliche-ressourcen/igraeser/ 
iFlora: www.i-flora.com/en.html
Wildpflanzenschutz Deutschland (Protecting Germany's Wild Plant Species): https://www.wildpflanzenschutz.uni-osnabrueck.de