Booking.com has found itself at the centre of a major system bug affecting some users of iPhones and iPads.
The problem first surfaced late last week when many users started complaining online about a crash that occurred on their iPads and iPhones when they clicked on hyperlinks in web browsers (Safari, Chrome) or from the native email client.
It then emerged that users only experienced the issue (no notification of an error, just a complete freeze of services) after they had installed the Booking.com app.
Some reports are suggesting the problem is based on the process of including so-called Universal Links (being able to open a link from a native app in another relevant app, such as YouTube or Maps) in an update for iOS9.
Some app providers, such as Booking.com, which associates its app with many links, are now believed to be causing the issues when opening web links because their databases are apparently too big.
Apple says it is working on a fix for the problem.
A Booking.com official says:

"We've uncovered some issues with the universal linking framework, which appear to be an issue specific to Apple iOS 9.3.
"We understand they are in the process of correcting, and we're offering any help we can to help them expedite a resolution."
The Booking.com app for iOS is currently on version 11, with an overall rating of 4.5 stars. The latest version, released on March 28, has 2.5 stars and countless reviews noting its association with the system crashes.