Both the Muwahhid and the Hafsid dynasties struck square dirhams with the same legends. The Muwahhidin struck them in simple Kufic and Naskh script.
Obverse:
لا اله الا الله
الامر كله لله
لا قوة الا بالله
There is no god except God
The whole commandment is unto God
There is no strength except in God
Reverse:
الله ربنا
محمد رسولنا
المهدي امامنا
God is our Lord
Muhammad is our Messenger
Al-Mahdi is our leader
After the fall of the Muwahhidin the Hafsids continued striking these coins in Naskh script, and at some point struck them in ornate Kufic script. The ornate Kufic and Naskh varieties are shown below.
Ornate Kufic script (Reference: Hazard 1952 #1123.)

Naskh script