I am working on an android app, which is developed using Sencha touch 2.4
While storing data locally when the device is off-line.
I need to store some images and some JSON data in the local store, how can I increase the size of local store? If these is any other way to store the data please suggest.
There is no way to increase size of localstorage. It's limited by browsers and usually has 5 MB limit. However, you can try WebSQL databases. You can start here: How can I request an increase to the HTML5 localstorage size on iPad, like the FT web app does?
Another options is to use AppCache API: http://www.html5rocks.com/en/tutorials/appcache/beginner/
Also, there are some tools from Sencha: http://www.sencha.com/blog/offline-techniques-sencha-touch/