Setup is a single line. Create your account, copy the snippet from your account page and paste it into your website. That is the whole install.
$9.99 a month. No contract. Cancel any time.
Create your account and pay. Open your account page and copy your personal snippet. Paste it just before the closing body tag on every page, using your site builder's custom code area if it has one. Publish your site.
Open your published site with ?synthtrail_test=1 on the end of the address, click through a few pages and submit a form. Wait about ten seconds, then open Sessions in your dashboard and press Refresh. Your test visit appears as a trail.
Any website that lets you add a script tag can use it. Your snippet contains your personal key, so keep it on your own sites.
Paste one snippet and see the synthetic visitors that use your site. Card details are entered on Stripe, never on this site.