Apps that are localized to their needs.
> Inferior substitutes for the Google/Facebook/etc infrastructure?
They aren't necessarily inferior. WeChat for example has a very intuitive privacy settings, which make a lot more sense than the complicated Facebook ones.
> Isolation from the rest of the world?
Many of these apps are expanding outside of China (To mixed success).
India has a thriving ecosystem of local apps, but with negligible protectionism [1]. Uber, Ola, Zomato and others do a great job of localizing for Indian needs. Based on recent experiences I'd say Uber does a better job than Ola in this regard, in fact.
When I visited Malaysia, several folks I spoke to said they have a similar ecosystem.
The best thing is that Indians/Malaysians don't have to give up Gmail or Facebook if they don't want to.
[1] At least negligible protectionism w.r.t other apps. Ola competes on equal footing with Uber, but both suffer from protectionism w.r.t. legacy taxi providers.
Many countries have protectionist policies, in particular in the automotive industry. The United States even had limits on Chinese parts imports[1]. China had an interesting policy to allow its automotive industry to grow through joint ventures with foreign companies (e.g. Hyundai[2]). They have done somewhat similar things with tech companies like Google and Microsoft, to nurther talent and guanxi[3].
Also in regards to Malaysia, the government has threatened to ban Facebook before[4], however not as a mean to allow local competition to grow.
[1] http://yaleglobal.yale.edu/content/protectionism-cannot-save... [2] http://repository.brynmawr.edu/cgi/viewcontent.cgi?article=1... [3] http://www.amazon.com/Guanxi-Art-Relationships-Microsoft-Gat... [4] https://globalvoices.org/2014/08/13/malaysian-government-thr...
Edit: Changed tense in regards to America's policy on Chinese imports.