Can IPhone3 software be upgraded without replacing the phone?

I have an old iPhone3 & Apps for any apple iproducts today will not download to this device. Is there any way to upgrade this iPhone without replacing it, just for the apps I don't want to render my device useless.

No, Apple does that on purpose to force users to buy new devices.
Basically all your phone is good for now is listening to music and looking at pictures. The current apps can't be loaded on to it as the iOS is too old to run them.