task-1: completed task.
task-2: wrote some test code for picking images through intents.
task-2: wrote some code for copying image to the app's picture dir on external storage.
task-2: wrote db CRUD operations for images info.
task-2: db bugfixes, wrote test code for viewing images in grid view.
task-2: images grid view bugfixes.
task-2: completed task.
task-3: completed task.
task-4: almost done task except adding/viewing comments.
task-4: completed task.