Server fees aren't an issue with this deployment as it's just a small static app, though if this were to be big it would be a load on the mediawiki API, so if there's more interest than this as a hobbyist side project I should serve some of my own and cache (as I'm loading a lot of images in parallel)
I looked up your pingtype project, it looks like it's for translating English <=> Chinese. Would that be for translating articles? For that I imagine I should add the feature for viewing Wikipedia in different languages.
The iOS app has a Wikipedia server built-in, for the articles.
The github page https://pingtype.github.io has only some smaller data cached, accessible through the top header row. Or you can copy-paste any text in.
Pingtype now supports over 28 languages, through direct links e.g. https://pingtype.github.io/greek.html
Github are very generous with their free hosting!
Check out Wiki2Touch for offline Wikipedia ideas, or pingtype (shameless plug) - just work out an open-source way to make it possible to reduce your server fees.