Webcamoid – take photos and videos with your web cam.
Kamoso – KDE/Qt application to shoot photos and videos with webcams. Lags a bit because it lacks settings to choose the video stream format.
Cheese – GNOME/GTK application to shoot photos and videos as well as test web cams under GNU/Linux.
OBS Studio – stream your webcam over the internet to Twitch or YouTube or just record it to a file on your PC, lots of advanced features and filters.