Looking at the screenshots on Softpedia here and here it appears to be available in English. Perhaps you choose language on installation, and haven't tried it myself (but was tempted to try at one time ) Let us know if you find out.
It installs in English language, but there are some alerts in Polish. It uses Bitdefender signatures.
Arcabit as a scanner is quite good...in last AVLab test of on-demand AV it scores the highest rank "best+++" (>99%) https://avlab.pl/sites/default/files/files/test_of_free_malware_scanners.pdf
Salutations/Greetings! Link for their Online Scanner,please? What is the cost in dollars their software? And can you purchase from the United States? Conflicts with other security software? For example Sandboxie? Zemana, ect... Kind Regards,
https://www.arcabit.pl/skaner-online.html Their basic product, Arcabit Home Security, costs 99 Zloty, which is around $27 US. I doubt you can purchase if from the US, but you will can purchase it from their website. Just use a Chrome based browser, and it will be able to translate the website from Polish to English for you. It should work fine with both Sandboxie and Zemana (just like any antivirus should). But, in my opinion, you'd be much better off with Bitdefender itself, or another antivirus using Bitdefender, so that you will be able to get English language support, as well as having an antivirus which is fully in English. If you don't like Bitdefender, you may want have a look at nProtect AVS. It also uses Bitdefender signatures, but the basic version is free.