Hi all,
I think it is too small for cichlids, but you may well be all right if you follow Vauxhallmark's recommendation. The best option would be a pair of Apistogramma borellii, but these are not easy to find and you have to be careful not to get A. "steel-blue" which are nice in themselves, but a lot more aggressive.
I like Killi's as well, and a trio of Aphyosemion australe would be great. Another possibility is Dario dario or D. hysginon, but all the ones I've seen for sale are males, and you would need a pair or trio. They are tiny but think they are cichlids.
A final option would be some of the more unusual Betta's, Betta imbellis? perhaps.
cheers Darrel