Is there any app that will allow me to hear through my phone's mic so that for example if I have a bad doorbell I can put my phone on top of it so that when it rings I can actually listen to it remotely on my desktop pc?
Yes, there is an app, if you forget your phone where did you put it like in the room or house. You can clap and find your phone, there is only one condition. your phone should be near enough to hear your clap noise. The App name is "clap".