KudosCRM
8.2#1 in email tracking softwareFrom $9 a monthFree planAndroidiOSWebAPI
Visit
KudosCRM suits sales teams that want pipeline visibility, synchronized email, marketing automation, and AI capabilities across web and mobile devices. The free tier fits small groups needing basic contact and activity management, while larger organizations can use higher user, contact, automation, and governance allowances.
Mailalert suits Gmail users who want free, unlimited open and link tracking through a Chrome-based extension. It is also relevant to users who prefer no registration and no branded tracking signature.