Question: Can somebody please suggest me when would I need a Level-Order Traversal (to solve some practical/real-life scenario)?

Answer: 
[Level order traversal](http://en.wikipedia.org/wiki/Tree_traversal#Queue-based_level_order_traversal) is actually a Breadth First Search, which is not recursive by nature.

From: <http://en.wikipedia.org/wiki/Breadth-first_search>

Breadth-first search can be used to solve many problems in graph theory, for example:

* Finding all nodes within one connected component
* Copying Collection, Cheney's algorithm
* Finding the shortest path between two nodes u and - v (with path length measured by number of edges)
* Testing a graph for bipartiteness
* (Reverse) Cuthill–McKee mesh numbering
* Ford–Fulkerson method for computing the maximum flow in a flow network
* Serialization/Deserialization of a binary tree vs serialization in
sorted order, allows the tree to be re-constructed in an efficient
manner.
Google Map Direction is using Level Order Traversal (BFS) all the time.

Algorithms repeat the same method choosing the node nearest to the intersection points, eventually selecting the route with the shortest length.

<http://blog.hackerearth.com/breadth-first-search-algorithm-example-working-of-gps-navigation>