Mobile app for intranet - made in online custom mobile app platform such as appypie etc..

We need a mobile app, which reflects our intranet. A requirement is that we do not want a custom programmed app, which we can not maintain ourselves. Therefore, a strict requirement is to have the app made in programs such as Appypie, [login to view URL] or other online custom app design platform. The app should be fairly simple and contain: A document library Contact list embedded community through API from existing [login to view URL] forum News section Optionally, we would like the app to contain: A chat option ability to embed pages from sharepoint communication site.