In reply to Nitin Gaur.

Nitin, even I have been trying to find an answer to keep "Spark" kind app active. SLT level push may have some initial impact, to really drive it, push has to be consistent. Apart from that if Spark app is integrated with email, with just partial message being visible on email client & get full message user has to login, it should do some more steering in behaviour change. Add to it an adoption plan similar to the UC adoption and some techniques from behaviour change science should help.