Amid the usual barrage of new launches around this time of year from the likes of Samsung and Xiaomi, I’ve been checking out the highest-end device yet from a manufacturer many readers won’t have heard of—but it’s one that marks an unusual collaboration with another brand that might be more familiar. Infinix is a sub-brand of Chinese company Transsion, which also owns the smartphone maker Tecno. The manufacturer is particularly successful in developing smartphone markets like Africa and the...