Application that searches the apartments to rent? Not really I would say.

not a good example. i can't find it now, but there was a story/comment about a realtor app that people used to sell houses. often when they were out with a potential buyer they had bad internet access and loading new data and pictures for houses was a pain. it wasn't until they switched to using a frontend framework to preload everything with the occasional updates that the app became usable.

low latency affects any interaction with a site. even hackernews is a pain to read over low latency and would improve if new comments where loaded in the background. the problem creeps up on you faster than you think.