The best alternatives to GLIDR are Productboard, ProdPad, and emojicom. If these 3 options don't work for you, we've listed a few more alternatives below.
With Upvoty you can make feedback boards for your users. Your users are able to submit new feature requests and are able to upvote on requests from other users. This way, you as the product owner, are always on top of which feature to build next.
ProductHero is a beautifully simple widget to publish in-app product updates and news, share the roadmap while collecting upvotes and feedbacks, track bugs and errors, chat with your users. It comes with a bootstrap like UI and dark theme.