A little known trick to make your wifi hotspot work even without a connection is to buy a coolpad.
The coolpad is a tiny device that is able to be used as a hotspot by plugging it into your router.
Using it to connect to a hotspots internet, you will see it show up as a separate hotspot in the list of devices you have on your router, just like it would normally.
If you are lucky enough to have a good internet connection, the coolpad will show up in the top right of the hotspot list.
This way you can connect to it without having to download an app and set it up on your internet connection.
You can find a list of compatible coolpad devices at the links below.
The Coolpad is available for $35 from the official Google Play store and at an average of $6 per day, it is not cheap.
That said, it will cost you nothing to make a hotspot that works with your internet.
Just make sure that you have internet access and the hotspots hotspot will work.
Source: The Verge via iRunFar