A Gtk3 GUI frontend (ojoc)
An urwid-based text-mode interface (nojoc)
Jodel (https://www.jodel-app.com/) is a GPS-localized anonymous (the users cannot identify each other) message board
OJOC (https://bitbucket.org/cfib90/ojoc) is a client for the JSON API (https://api.go-tellm.com/api/v2) exposed by the Jodel server.
It is written in Python. Frontends exists in two versions:
A Gtk3 GUI frontend (ojoc)
An urwid-based text-mode interface (nojoc)
Nowadays, elaborate authentication schemes are used which means OJOC does not function properly anymore...
In early 2016, no authentication was needed whatsoever -- everyone with knowledge of the API could request an access token and post messages.
Then, a HMAC-based authentication was added with the necessary key contained in a native library delivered as part of the APK. It was delivered in plain text at first, but is encrypted using a XOR-based cypher now.
The OJOC-keyhack project (https://bitbucket.org/cfib90/ojoc-keyhack/) is an attempt to retrieve the key from the native library automatically.