Services under Free-Tier Truepush Onesignal
Unlimted Web Notification
Unlimted Mobile Notification
Unlimited Subscribers – Web
Limited till 30k subscribers
Unlimited Subscribers- Mobile App
Unlimted Custom Tags Limited till 10
Templates Limited till 3
Unlimited Segmentations Limited till 6
RSS-to-push Through Zapier integration)

 

The common features like multi-browser support, Unlimited projects, Unlimited Websites/apps, Analytics, etc.  are provided by nearly all the push notification platforms.