When I started at StackShare, I needed an easy way to create a pipeline of the different partners we were engaged with, and track the status of those conversations. Having just begun to explore partnerships in earnest, our needs at StackShare don't necessitate something as robust as Salesforce Sales Cloud, Close.io or similar offerings that exist.
Nevertheless, I didn't want one more Google Doc to track things either, and I heard about Streak, so I figured I'd give the free version a try. So far, it has accommodated everything I need, and it integrates simply with Gmail which meant I had it running in a few minutes. You can create a pipeline entry directly from an email thread, which I find useful compared to logging into a separate platform, and there is basic functionality for scheduling follow-ups and tasks. The pipeline stages are fully customizable as are the fields you can add - (I added a note field to explain why someone may be in the "Backburner" stage, for example).
As we scale our Business Development initiatives and grow our team, we'll likely need to look at upgrading Streak or incorporating other tools like Yesware. But, for a quick and easy way to organize a sales pipeline and track the respective conversations, the Streak free version nicely accommodates what I need and has been very helpful in managing discussions with a variety of partners thus far.