TestFlight - iOS beta testing on the fly.
TestFairy - Painless Beta Testing
Boombox.io - iOS devs rejoice! Embeddable HTML and hosted TestFlight beta sign-up forms.
TestApp.io - A platform that helps both mobile app developers and owners to easily share their apps with everyone to get feedback before reaching publicly to Google and App stores.
DeployGate - DeployGate enables developers to distribute beta apps to enable beta testing from fellow developers and community.
Visual Studio App Center - Continuous everything – build, test, deploy, engage, repeat