Eyezy is a real, operating company - people do pay and do receive a dashboard - but "legit" is the wrong question, because legitimacy does not tell you whether it does the job you need. It is a broad consumer monitoring app aimed at parents, and its limits are the same ones every vendor in this category hits.
What it actually does. On Android it installs as a normal app with wide permissions and reports social-app activity, messages, location, screenshots and keystrokes depending on tier and root status. On iPhone there is no device-level agent - iOS does not allow one - so it reads an iCloud backup, which requires backups enabled and your Apple ID credentials. No live iMessage reading, and no remote install despite what resellers claim.
Check before you pay: the renewal price rather than the introductory one, which features actually sit in the tier you are buying, and whether the vendor's own pages claim iPhone message capture. If they do, treat the rest of that page with suspicion.
Disclosure: we build Ultimate Phone Spy - SMS, call log, location, web history and installed apps on Android 4.0+, Windows and Mac, at $69.90/month, $40/month quarterly or $16/month annually (pricing). We do not support iPhone, stated plainly on system requirements.
Start free where you can - Apple Screen Time, Google Family Link and Find My cover limits and location at no cost, enforced through your own account credentials.
We covered the longer version in this thread.