There are tons of content locker plugin available ( both free and premium version ) but only a few can serve for desired purpose. Some are okay as free version, while some others are useless without an upgrade.
Social Locker Cat is free and useful,
I started using Social Locker cat WordPress plugin in an online test I developed, I needed to figure out how to get people to visit the site and content locking was a good idea. And It worked, with more than 85 Facebook shares per day. All I had to do was to put [Iockercat] [/Iockercat] code in between the Test.
So my experience using this plugin will make up the review
1) lightweight (but less flexible)
2) Clean and responsive. I tested the content Locker plugin with opera, firefox, chrome, UC . It was working very fine, both mobile and PC .
3) Social Locker cat has two important networks ( Facebook and Twitter) free.
1) You cannot use custom title/description on the post you want to implement the locker. I don’t think you should be worried about this or maybe you should.
2) It only has 2 Networks ( Facebook and Twitter), I contacted their support to see if there are additional network and they promised to build the premium version only after the success of the free one.
Here is an excerpt of their response
Social Locker Cat was a bit of an experiment. We had hoped to build a premium version, which would probably have included WhatsApp, but the free version has not done super well.
So we won’t currently be putting more development effort into expanding this product. The plan is to hope it grows organically, and perhaps down the road we can release something a lot more feature rich. I’ll mark your request down with some others for now.
Based on my experience, I would give this plugin 4 /5 star. One star off for not having other Social networks available.
How about you test if it is working?