Google subtly let go of the iOS and Mac version of Sparrow from its list of clients in Apple store. It now opens opportunity for Inbox which by the way, is their very own utility app. We can clearly remember how Google paid Sparrow a sum of about $25M (in US dollars) in 2012 and lined it up in the list of purchasable applications in the Apple store. Just last autumn (of 2014), the biggest internet service provider opened Inbox by Google via invitations.
Sparrow had captured the interest of Google business-wise due to its unique e-mailing features. In retrospect, iOS and Mac users were ready to download from the Apple Store at a price of barely $3.00. However, Sparrow gave nosedive-like graph in terms of service due to its lack of developers. Currently, it takes its place at the 842nd most downloaded iOS (or Mac) application.
Meanwhile, Google did not remove support for the present Sparrow users, but hopes for them to do a test drive on Inbox. As aforementioned, Inbox is free as per special invitation only. This hot app is a good aid for mail sorting and snoozing. It also allows you to retract your sent mail even before the recipient reads it. The email app is also made available for Android users which make up at least 70% of its users while there is only a 28% from iOS users. You can ask for an invitation by simply sending a request to inbox@google.com.