App Signal Messenger went down for 24-hours on Saturday after 8.8million people downloaded the encrypted service
The exodus was caused by rival WhatsApp s January 4 message on its controversial privacy update
The firm was criticised for sending the notification, which seemed to suggest changes to the data it would share with its parent company Facebook
According to data from analytics firm Sensor Tower, Signal was downloaded 246,000 times in the week before WhatsApp announced the change, and 8.8 million times the week after
In the US, downloads went from 63,000 to 1.1 million, with numbers jumping from 12,000 to 2.7 million in India and 7,400 to 191,000 in the UK