After working on many wireframes for a website, I want to run usability tests with distant users, is there any tool or way to get users opinions ?
Typically, it's best to be careful about soliciting opinions from the general public. They lack UX experience and the general public is not innovative at all. It's far more objective (and therefore effective) to run A/B tests on specific metrics to see what performs better. You can use tools like Mouseflow or Inspectlet to track users' habits and see where and how they interact. There are a thousand A/B testing tools out there. If you're using a content management system, there's likely one built in. If not, even Google has a tool.
When you can see what's failing and you can prove it with data, your design choices will be more informed and most of what you create will show improvement. In essence, the steps are as follows: Observe, Innovate, and let them compete. After that, run it again and again until you retire.
There's a quote from Cruise Industry News Quarterly that grew and changed into something falsely attributed to Henry Ford. I don't know a single UX professional that doesn't hear "Ford's Wisdom" from someone on a monthly basis. I leave the original quote here to ponder:
"I mean, if Henry Ford canvassed people on whether or not he should build a motor car, they'd probably tell him what they really wanted was a faster horse. But designers do have to be more adept at knowing what target markets want."
If you absolutely must get user feedback, your best bets are likely either Hello Bar or IdeaScale. They're purpose-built for this kind of work. You could also just have a feedback page with a text area for them to type into. Still, please consider what I mentioned above.