Get package from github releases and install with File Explorer
Tip
This app is a part of Stick firmware app-pack, if you installed app-pack on first boot, you don't need to install it again. Remember that app-packs can be slightly older than the newest version of this app.
Go to https://convert.kitki30.tk/ upload file and press download to get converted image, your file doesn't go outside your computer, it is processed locally using your browsers javascript.
To use image viewer you need to convert them with converter.py
To use converter.py you need to install pillow using pip install pillow