If you don't know what to do with your Kobo in terms of modifications, there are three main paths that you can follow. These paths are not mutually exclusive -- you can follow all of them at any point if there are modifications from all three that you'd like to make. In all cases, should something go catastrophically wrong, your issue will likely be fixable with a manual factory reset.
The default system reading application is often referred to as "Nickel".
Windows users: You should enable hidden files
Kobo's directories start with a period in the front, which mean that your operating system might hide them from you by default.
macOS users: You should disable automatic extraction
Safari automatically extracts ZIP files by default, which may not always be desirable (especially when using the one-click packages). You can disable this feature by following these instructions.
Custom software, for the most part, does not replace Nickel -- it runs alongside it as something that you can launch after boot. Think of it like how you install another application on a computer or a phone. The goal here is not to modify Nickel -- the goal is to install software that will allow you to run software other than Nickel.
The instructions given here will use the one-click install packages to install the following:
- NickelMenu, a customizable set of menus that can be used to launch applications from your home menu, as well as to add menu options to your reading experience
- Kute File Monitor (KFMon), a launcher that uses images to launch applications
- Either or both KOReader and Plato, alternate reading applications with additional quality-of-life features that may not be found in Nickel
Nickel modifications refer to changes made to Nickel to change your reading experience. While NickelMenu is a form of one, the changes referred to here will be done through a tool called KoboPatch. The tool will be used to make a modified Nickel that will be installed to your device, featuring all Nickel features plus whatever modifications you've decided to make.
The instructions given here will use the kobopatch forum thread to install patches of your choosing.
These refer to changes or additions that can be made simply by creating files/folders or by modifying your
Kobo eReader.conf file. These are things that are built into every Kobo by its developers.
The instructions given here will not be linear -- they'll be more of a list of things that you can do.