I've tried most of the services offered to support beta testing of apps, and believe TestFlightapp.com was by far the best.
Apple must have thought so too, as it acquired them with Burstly in [February 2014](http://www.theverge.com/apps/2014/2/21/5434060/apple-buys-maker-of-the-ios-testing-platform-testflight)
Beyond the almost immediate axing of support for Android apps, TestFlightapp.com's public twitter and blog fell silent and Apple began the job of internalising beta support into the appstore. At the WWDC in June 2014 they announced the integration of TestFlight into IOS8 and iTunesConnect.
Today they've [announced](http://help.testflightapp.com/customer/portal/articles/1768754) that access to TestFlightapp.com will cease in a month's time on 26th February.
The version of TesfFlight that is integrated into the app store has some huge advantages. Mostly these are due to the fact that the old Ad-Hoc release process is no longer necessary. Gone are the days requiring device UDID's to be managed, provisioning profiles created, special versions compiled etc. Not only was this a huge overhead on time, developers were faced with a hard limit of 100 devices registered for testing with their account, which is no where near enough if you've a couple of apps - given the range of iOS versions and devices and the dependence on testers with perhapslimited time and goodwill.
With the new TestFlight, you simply add the Apple Id for the people whom you want to invite to access the pre-release. You can have 1,000 per app, and each can have multiple devices tied to their Id. The binary that you compile and upload is the same as you'd submit for the app store - so there is no danger of creating a release version that is different from the adhoc version as I once did.
So much for the good. However the whilst the new integrated TestFlight makes distribution so much easier, it has almost nothing worth while to offer for the collection, de-symbolication and presentation of crash reports. Nor does it offer any level of usage tracking to ensure that all parts of the app have been used - and only the scantest of reporting on which devices or IOS versions have been used. These are all essential parts of running a test program.
Improvements in the handling of crash reports are promised for this year - but I do not yet know any further details or timing.
I also believe that its still necessary to support at least IOS7 - which the integrated TestFlight won't allow.
The old TestFlightapp.com did continue to give crash reporting and allow IOS7 testing. With that being retired, developers will be forced to look at using 3rd party alternatives - at least until TestFlight offers better crash reporting and we're happy to ignore IOS7.
So it's one step forward, but another one backwards.