I love Locus map supporting multi-lingual maps. I'm heavily using Openandromaps in China switching between Chinese and Pinyin. The constant switching is a hassle, though. What I'd love to see is that two languages are displayed simultaneously. Navigating in non-Latin script countries would be so much easier then.
(this wish was also mentioned in http://help.locusmap.eu/topic/multilingual-vector-maps)