shahbaz200 :
What do you mean by load balancing? You mean if one connection gets slower, the other with more speed kicks in? If yes than you can use Connectify Dispatch that does the similar thing.
The thing with that is that the phone has to be in range of it's hotspot, it can't be run off the router.
Although if you run the phone with a hotspot and have systems connected to both and are OK with the range, that software looks to be OK. But it won't do anything with using the router for that, that second WAN port won't be able to be connected to the phone.
Maybe if you setup a wireless extender, connect it to the phone hotspot, hook it up to the WAN port with the Ethernet cable and turn off DHCP on the phone it would feed the second WAN port.