I’ve found references to a couple of African scripts that I thought were interesting enough to post; I’ll link to the Wikipedia articles and quote the first bit of each:
Nsibidi (also known as nsibiri, nchibiddi or nchibiddy) is a system of symbols indigenous to what is now southeastern Nigeria that is apparently an ideographic script, though there have been suggestions that it includes logographic elements. The symbols are at least several centuries old—early forms appeared on excavated pottery as well as what are most likely ceramic stools and headrests from the Calabar region, with a range of dates from 400 to 1400 CE. […] The origin of the word nsibidi is not known.
The Bamum scripts are an evolutionary series of six scripts created for the Bamum language by King Njoya of Cameroon at the turn of the 19th century. They are notable for evolving from a pictographic system to a partially alphabetic syllabic script in the space of 14 years, from 1896 to 1910. Bamum type was cast in 1918, but the script fell into disuse around 1931. A project began around 2007 to revive the Bamum script.
I expect everyone knows about
https://en.wikipedia.org/wiki/Zaghawa_alphabet
which is certainly the only script I am aware of derived from camel brands.
(I am sure everyone knows about Vai and N’ko. IIRC we had some discussion of them before.)
If I knew about the Zaghawa alphabet, I’d forgotten, so thanks for that!
Thaana, which is now the standard script for Dhivehi, the national language of the Maldives, is written with letters derived from digits, of all things. The first nine are basically the Arabic digits 1-9 (written with a slant), the next nine are the Indic digits 1-9 from the former script used for Dhivehi, and the remainder are derived from the preceding groups with diacritics. The vowels are marked with Arabic vowel marks, but they are not optional.
Apparently this scheme was adopted in order to keep the many Arabic loans separated, but visually coherent, with native Dhivehi words. Arabic loans are almost always written in Thaana rather than Arabic nowadays, however. The alphabetic order of Thaana is neither Arabic nor Indic but seemingly quite random, so the script may have begun as a cryptogram.
The End of King Njoya and the Bamum Script:
Lameen has posted about a new Songhay alphabet.
I see the link I posted 2 years ago is already dead. The Archive says it went offline shortly after I posted it; the last version is here.