Changelog

Changes since 1.1.0

Improved compression. Compression should now be optimal. UMM should now be able to compress at least as well as any other tool.
Now shows how many bytes away from successfully compressing a mod was, if within 48 bytes.
Extra logging to a log file can be enabled by putting a file named "debug.flag" in the UltimateModManager directory.
Currently installed mods will now be highlighted in blue. Note, this is only applicable to mods installed after this update. To remain fully compatible I recommend restoring all backups after updating to this version.
Mod paths are no longer case sensitive
General system stability improvements to enhance the user's experience.

Place the NRO in sdmc:/switch/
Put mods in sdmc:/UltimateModManager/mods in any folder structure. Folders at the top-level here will be the selectable modpacks. Compressed mod files may start with their offset in hexadecimal, such as 0x35AA26F08_model.numatb or be named by their path within that ARC. All uncompressed mod files must be in the ARC folder layout and have the correct original naming. An example of a correct uncompressed mod would be UltimateModManager/mods/organized_css/ui/param/database/ui_chara_db.prc, and it would show up in the application as organized_css.

Use the DataArcDumper to dump your data.arc first if you have not. If you want to use this functionality, please start the HBL by overriding Smash itself, which is done, by default, by starting Smash while holding the R button.
Use the FTP server to transfer over mods to your Switch over your Wi-Fi connection. Open this server, use its IP address in conjunction with a FTP client like WinSCP. Completely optional, as mods can be transferred in any other way as well.
Use the Mod Installer to install mods. Any time a mod is installed, the corresponding vanilla files will be populated as backups. If at any time you want to uninstall all mods in the data.arc, press the option to restore backups or uninstall individual mods with the Y button.