Apple TV 3rd generation remotes actually use Infrared (IR) technology, so you should be able to just use the Apple Remote. The only reasons your remote may not work with the Apple TV are:

• A dead battery
• you have previously linked the remote to another device (e.g. a Mac)

So, if your Apple Remote is not working with your Apple TV you can replace the battery and/or link it to your Apple TV.

1. To replace the battery refer to How to replace the battery in your Apple Remote. Once you've replaced the battery, if it doesn't work with your Apple TV, then try the next step.
2. To link the remote to your Apple TV you can just press and hold the Menu and Right buttons simultaneously for five seconds.

As an aside, you may also find that using the same SSID name and password for your new Wi-Fi network (as you did for your old one) means that your Apple TV will be able to connect to it.

I decided to answer my own question after 2 hours of figuring out ways around the problem that "If home sharing is not turned on, apple TV cannot be controlled with an ios device".

Note that I am talking about a 2nd gen apple TV. A 3rd gen can be worked around by http://support.apple.com/kb/HT5900?viewlocale=en_US&locale=en_US

You actually can get the 2nd gen synced with your ios, a little sneaky but it is easily managable.

Here is what you do...

1. Connect the apple TV to your laptop and reset to factory settings on the apple TV (I did this to get a clean box + latest software update).

2. Now when apple TV powers up (just hook the HDMI to the TV and the power up the apple TV) it will ask you for a bluetooth keyboard pairing if needed (if you have one, rest is straight forward, if not go to step 3 else step 5). New versions of apple TV software ask you for this pairing, hence the restore to factory + software update on the apple TV. NOTE: Restoring may not work on a Mac running Catalina, perhaps because Apple broke the functionality when they decided to remove iTunes. On MacOS 10.15.2 it gave an "unknown error (1)" and left the Apple TV stuck in recovery mode (showing the "connect to iTunes" screen when plugged into the TV). However it seems to work fine on macOS Mojave which still has iTunes.

3. I do not own a bluetooth keyboard so I downloaded 1keyboard app from the app store for free (I own a mac, something like this should be doable for windows too).

4. Using 1Keyboard I could emulate a bluetooth keyboard functionality from my mac.

5. Once I had the keyboard connected to the apple TV, use up down etc. keys to navigate and setup your apple TV. Then go to settings and pair your ios Remote App.

6. Save 20$ by not buying the remote :-)

   Hope this helps someone.