Hero Hunters Offline options are available, but are limited in what you can do. You do not need the internet to play this app though a few of the option wont be available like PvP among others. Many people are looking around online for an offline version of the app and it most likely doesn’t exist. Others may offer links to suck content, but the download if any are corrupted and wont work properly.
If your planning on getting the most out of this app then your going to want to play with an online connection. Since there are a seemingly large amount of players that wont offline you’ll only get to take advantage of part of the game. Another things that you’ll be missing out on is the purchases.
Daily rewards are obtainable while you do not have internet connection. Many games can be manipulated by changing the clock in your devices settings. I’m not sure if it can be done with this app, but if you can than you would be able to speed up the rate of getting daily rewards.
I might be a good idea to not even install apps that are promising extra things like offline play. For experienced players, they should already know that an offline game that is originally an online game will probably not be playable in a modded app. The chance that the app is contaminated with a virus or other hacky things is pretty good. There are a few reliable websites though that will allow you to download modded apps with real mods. If you find Hero Hunters on one of these websites it might be worth checking out as it will probably work.
If your interested in more related information you can check out the Hero Hunters Wiki.