Would I infringe on patent rights, if i develope a device that produces the same end product but has a different way of executing it?

The answer depends on what exactly other people have patented. To determine that, you must look at the "claims" in their patents. If your app is performing each and every step or has the same structural elements listed in just one of their patent claims, you are infringing their patent. You can also infringe if your app makes only an "insubstantial difference" from just one of their claims. You need to consult a patent attorney to review their patent claims with regard to what you are doing. Also, consider having a patent search run. There are many patent applications and issued patents that don't have a commercial product, and you could be infringing those patents as well.