install input-modifier. from the AUR (either manually or with your favorite helper).
download the installer from here (don't download the source code versions!).
after downloading input-modifier, please follow these instructions for a proper install.
input-modifier comes in a universal binary package, besides some distribution-specific packages. this means it will work with any distribution. this is possible because input-modifier has no dependencies other than udev, which is found in almost every single modern distro.
input-modifier doesn't run as root, to allow for multi-user support in the future.
to install input-modifier, first extract the installer. and type the following in a terminal:
tar -xvf <RELEASE>
(replace with the name of the input-modifier package, e.g. imod-v1.2-x86_64.tar.gz)
this will extract the installer to a directory named input-modifier.
to run the installer, type:
cd input-modifier
sudo ./install
this will install input-modifier to your system after you accept the prompts.
input-modifier opens input devices (of course), so it requires you to be in the input group.
you can add yourself to that group by typing the following:
sudo usermod -a -G input $USER
after this, you'll have to re-login before being able to use input-modifier, since new groups don't apply until you do this.
under special circumstances, a reboot may be necessary.
after this, you're ready to go. see startup.
this can't happen, because of the udev rule that has to be installed.
plus input-modifier has no dependencies, so it wouldn't make sense.