The best thing about this software is its speed, you can check your resume in less than 1 minute! I think it's not great for resumes with complex formatting like tables or pictures because most templates are too basic (just text).
For those who have simple/basic formats only - there will be no problems at all using cvcheck as their main tool while searching new jobs through online job boards etc., especially since they offer an easy way out from having multiple copies / duplicates when applying several times simultaneously via different websites e-mail addresses & phone numbers which results into many rejections due technical errors by employers' HR depts..