Burr,
I've added some logs statements on the client and basically it seems it can not parse the response from the server :
I/Web Console( 1386): textStatus: parsererror at file:///android_asset/www/js/index.js:103
I/Web Console( 1386): error: SyntaxError: Unexpected end of input at file:///android_asset/www/js/index.js:104
If I do a CURL like this :
I got an correct answer but the content type is 'text/plain' , please check your rest endpoint to be sure it's producing json as output, that should solve your issue.
Could you also paste the commands you used in Forge to scaffold the REST endpoints so that we can check there hasn't been an incompatibility introduced ?