There aren't many free VPNs I feel comfortable suggesting, let alone using. But I love ProtonVPN for when I need a quick US connection for free, especially for anything region-blocked. I wouldn't bank or do anything sensitive with it, but I've had great success with its free version over the years.
I use Sucuri's premium protection plan to keep bad guys out of HIF. I can't recommend them enough!
WP Rocket caches the entire site to improve site speed and make sure the site doesn't crumble if you invite 1000 of your closest friends.
Adding new readers to HIF's newsletter helps grow the site, so I use Thrive Leads to show new users (and only them!) a popup asking to join. The stats and A/B testing are key to discovering the line between helpful reminder vs. annoyance.
Managing every social media account is a time sink, but CoSchedule handles Facebook, Twitter, G+, and Pinterest all from your WordPress admin.
Once you get beyond 100+ posts, it gets ridiculously hard managing links.
HIF has over 4,000.
Pretty Link Pro helps alleviate this problem by giving you a central admin panel to view, manage, and update your links. They have real-time stats, the ability to rotate through multiple links, and tons of other great features.
They're not the cheapest, but you get what you pay for with domain registrars. Namecheap's amazing support makes them worth the extra pennies and you can always find a code for free privacy WHOIS!
It's amazing how many spam comments get fired at a site daily. I'm talking thousands by the hour. Akismet puts up a wall, for free, and stops 99.999% of all the bad comments.
Large amounts of info can be hard to display. Sometimes tables work best, like on our birthday freebies page!
HIF wouldn't work without tips & ideas from fellow Hiffers. Gravity Forms handles those and so much more by powering our contact forms. With conditional logic, our single contact page is able to field requests from readers on any topic, from submitting a freebie to reporting an expired offer to asking for tech support, and always deliver the message to the right inbox.
And thanks to their wide array of extensions, Gravity Forms handles all of HIF's surveys, contest entries, and customer invoices!
Honestly, I'd be rudderless at HIF HQ without Gravity Forms.
S#*t happens. VaultPress saves the day. Rinse, repeat. They provide real-time backup of all my files plus the ability to rollback to a previous safe versions. There are cheaper alternatives on the market, but they tend to either not work as well, be more cumbersome to setup, or a variation of those two. VaultPress is made by Automattic, the parent company for WordPress, so you know it's well coded and built to work.