Product Hunt
One of the best parts about being a product manager is that you can actually call installing new apps and signing up for new things part of your job. I really believe that you cannot keep track of what is going on with just reading and not actually installing and signing up for new stuff regularly.
There are multiple things you can use to discover new stuff, but one of the best places to go to is Product Hunt. Doing some research can be something to schedule. Another way of doing this is to install their browser plugin that will display a section of what is currently trending.
When I’m signing up for a new service I’m always looking at the experience as a new user, how smooth is it? What kind of emails do I get? It is also interesting to notice what kind of products triggers you to install. I’m sure you’ll pick up some things you can bring back to work!