Seamilar is a plugin for Cinema 4D R16, R17, R18, R19 available for Windows and MacOS, which allows to easily unwrap and edit UVs.
Included in the plugin is a specific UV View window allowing the visualization and editing of color-coded UV islands.
It contains a tool to create seams, which can be used in the 3D view port as well as in the dedicated UV View window. Next to this, the native Cinema 4D selection tools for edges can also be used to create seams.
Basic move, rotate and scale tools are available to manipulate UV points, edges, polygons and islands. Snapping and quantization can be enabled as options. The move tool even has a snap-to-pixel option.
Additional tools are made available to align the UV items, as well as pack islands.
A multi-object mode is available, which allows to position and arrange multiple objects onto a single canvas.
The UV View has 4 display modes, allowing to visualize the UVs in shaded, stretch, checker or texture mode.
Comments, suggestions, ... please do so in the dedicated thread only, thank you.