Corona SDK is a great tool for making making apps. Best thing about Corona is it saves a lot of time. If you looking to make a non-game app with Corona SDK , you made a good decision.
There are some high quality non-gaming apps that are built using Corona. One of the best examples ia the ToDo task list app at TaskPadPlus
This is a Utility app that is built with Corona SDK.
These kind of apps are all about saving and updating the data. These kind of utility apps can be made using JSON files. The simplest way to create is to save the data in the form of a json file and update it or add it or delete it. If you want to built it in large scale , you can use a back end built on Apigee or MYSQL to save and retrieve data.
A simple saving and updating a json template can be found in this Word shuffle Corona App template