The immediate popup that wants my email is annoying. I get why sites have this but letting you know everybody hates these popups.
None of the categories work if you click the main landing page icons but do work if you click the drop down Suggestions menu (on the desktop version, using Firefox 60.7.0esr however the mobile version the main icon category links work).
The Features options (which are hard to use on a mobile screen) have nothing to explain what they are, and assume knowledge of the reader. These options under Features to narrow the product listings could probably just be a single tick instead of no/yes boxes too. For example 'Accepts paypal' could be just one tick, instead of 'Yes/No/Unknown'. There is also inconsistent design here, with some pages listing 'Pricing: Free/Paid' as tick options then other pages 'Free Plan: Yes/No' 'Paid Plan: Yes/No'. I would pick one consistent design. You may also want to audit your site for accessibility compatibility, lot's of img alt text does not convey the same information as the image.
There should be some kind of caveat/more info about audited category, since it doesn't mean much if the person writing the software is a well known PhD crypto engineer, such as Tarsnap. Who is qualified to audit it? Who did the auditing and where is this information, seems like this should be included in the product summary instead of a no/yes answer. The 'Naughty List' could easily fill up with a thousand entries, you'd want to add that to specific category pages like https://prism-break.org/ does though I would personally avoid telling people what not to use, every product has had some kind of security breach. Finally the summary under some of the products as "Security Issues: Good" is worthless, as again none of the feature categories are explained anywhere. For example you list Telegram as 'good', but if you ask Moxie Marlinspike about it he'll give you a laundry list of severe unaddressed Telegram problems and shady practices so this is another impossible category. The upvoting seems like it will just be gamed by companies to shill their product, I don't see a benefit. Maybe you could offer reviews instead but make them specific reviews, like QoS, not allowing for useless star reviews or free text where random people can rant "This is run by CIA" or whatever.
Edit: extra work, but you could think about pricing tier filters, since let's be honest that's what most people care about. "Show me the cheapest options" like how logical increments website works https://www.logicalincrements.com/
Edit2: you also may want to look through these slides, they focus on general UI design http://www.cs.cmu.edu/~bam/uicourse/05863fall18/schedule.htm...