Also two journals to mention here :

• The graduate journal of mathematics (The Graduate Journal of Mathematics is an electronic journal that publishes original work as well as expository work of general mathematical interest which add to the literature, have pedagogical value and help make more widely accessible significant mathematical ideas, constructions or theorems).

• Journal des élèves de l'ENS Lyon, (original work, expository work and recreational maths, but I don't know their current policy about people not studying at the ENS Lyon and wanting to submit there).