Depends on what you want to build but I'll offer you look into CouchDB/PouchDB for backend data/authentication and jQuery/Bootstrap for the front end. This let

Depends on what you want to build but I'll offer you look into CouchDB/PouchDB for backend data/authentication and jQuery/Bootstrap for the front end. This lets you code most all of the app functions in JS so it runs almost entirely on the client side, provides what's needed for offline use, syncs the user's client side data with your server automatically or on demand, and gives you a reactive front end that will run on most any device in a web browser. The docs for all of those are first rate with lots of example code to get you started and CouchDB/PouchDB have great community support.