Requires macOS 10.12+
Tags are a very useful file organization feature in macOS. A file can only ever live in one folder at a time, but a file can have multiple tags at the same time, and so can live in multiple "places" at once. For example, you might want to tag the same photo as both Vacations/Hawaii and Environments/Beach.
Unfortunately Finder's tagging interface is limited and awkward to use. Tagception lets tags in macOS live up to their full potential with easy drag-and-drop of files into tags, nesting of tags to any depth, and a grid view optimized for images.
The sidebar on the left has three sections:
These are the default tags that come with macOS. They have fixed colors and cannot contain nested tags or be renamed.
This just shows the folders under the current user's home folder. Folders are not tags but they are still shown because they give you an easy way to tag files that don't already have a tag.
These are all of your custom tags. Right-click on Tags to add a new tag, and right-click on an existing tag to add a new subtag (a nested tag). Subtags show up as nested in Tagception but will show up as a top-level tag in macOS Finder, with one forward slash for each nesting level.
The grid view on the right shows all files related to whatever is currently selected in the left sidebar. If a folder is selected it will show all files in that folder, and if a tag is selected it will show all files with that tag.
Click in the sidebar to select a folder or a tag, then click on a file in the grid view to select a file. A selected file can be previewed quickly by pressing spacebar which opens a QuickLook preview for that file. Double-clicking on a file jumps to macOS Finder and selects that file to help you locate it.
Drag one or more files to a tag to add that tag to those files. You can select multiple individual files with command-click and a range of files with shift-click. You can also drag-and-drop files from other applications (such as macOS Finder) into Tagception to tag them.
You can remove a file by selecting it and pressing the delete key. If you have a tag open then it will remove that tag from the file, and if you have a folder open then it will move the file to the trash. Tagception supports undo/redo for all operations so you can undo the delete with ⌘Z if it was unintentional.
Here are some more advanced behaviors that you may find interesting:
To move a tag (and all of its subtags) inside another tag, select the tag in the sidebar and drag the tag on top of the new parent tag. This is analogous to moving a folder inside of another folder, except of course that it operates on tags. What this actually does is to rename all tags belonging to the moved tag so that they end up inside of the new parent tag.
Sometimes you may want to quickly mark a few files to set them apart from the rest, usually when reviewing a large number of files. This can be done by clicking on the ★ icon when hovering over a file. Under the hood this just adds or removes a special tag named ★ which is the only tag that doesn't show up in the sidebar.
If you want to select a large number of files and you don't want to hold down the command key for a long time, you can instead click the ☑ when hovering over a file. This enters selection toggle mode which allows you to toggle whether a file is selected by clicking anywhere on that file without holding the command key. Deselect all files (e.g. by pressing the escape key) to leave selection toggle mode.
If you want more space for the grid view, you can drag the boundary between the sidebar and the grid view to resize the sidebar. You can also expand or collapse the sidebar completely with the ⌃⌘S key combination.
Tagception has a window interface that's similar to Safari. You can create a new window with ⌘N or a new tab with ⌘T, which lets you look at multiple tags at once and also drag-and-drop files between them. You can also navigate backward and forward in your navigation history with ⌘[ and ⌘] or by clicking the left and right arrows in the top right corner.
A tag or folder can be expanded and collapsed by clicking on its triangle icon. If you want to also expand or collapse everything under it as well, you can do that by option-clicking the triangle icon.
Tags on macOS are "extended attributes" and are a regular part of Apple's file system. Any existing syncing system that supports syncing macOS extended attributes such as Dropbox may be used. Keep in mind that only other macOS computers will be able to see the tags.
Initial public release.