GetResponse started in Poland and has grown into a proper multi-tool for online businesses. The core offering is email marketing, which works fine if you're not expecting Mailchimp-level polish. Where they've done well is bundling everything together: website builder, landing pages, automation, and web push notifications all in one account. The website builder uses AI to speed things up, which is handy if you need something live quickly and don't want to faff about with code.
Their comparison pages (versus Mailchimp, Constant Contact, ConvertKit and others) are worth reading because they're honest about where they sit in the market. They're not the cheapest, but they're not trying to be premium either. It's solid mid-market software. Customer service gets mixed reviews, so don't expect hand-holding if you hit a problem.
One thing worth knowing: GetResponse runs a lot of promotional nonsense. The free trial blue banner at the top of their site is there to push you towards paying, which is normal but worth being aware of. They're also keen on comparison marketing, which suggests they know their real competition isn't feature parity but rather convenience. If bundling matters to you more than having the single best email tool, they're actually a reasonable pick.