Worryingly for Twitter, whose advertising business has seen better days, there were notable declines across all nine markets over the period.
In the US, time spent fell by just over five minutes, from an average of 18.73 minutes a year ago to an average of 13.50 minutes this year. Brits also now spend about four minutes per day less on Twitter than they did a year ago.
It's a similar story for Facebook-owned Instagram. Average time spent on Instagram in the US fell by 10 minutes to 19:93 minute per day. There was also significant drop in time spent on Instagram in Spain, the UK and South Africa, where year-on-year declines ranged between four minutes and eight minutes.
SimilarWeb's figures for Snapchat roughly align with the 25 to 30 minutes per day the company's 100 million users reportedly spend in the app.
According to SimilarWeb, time spent on Snapchat in the US was 23 minutes a year ago, but that fell to 18 minutes in Q1 2016. Regardless of the decline, the report suggests Snapchat is outperforming Twitter currently.
The study also looked at the percentage of devices that each of the four apps are currently installed on and found across the board declines here too.
Facebook once again dominates current installs, with its lowest figure recorded in Germany where it was installed on 63 percent of devices a year ago, compared with 55 percent in the current quarter.
In the US, Facebook is installed on 68 percent of devices, compared with 71 percent a year ago. Similarly in the UK, installs are down from 73 percent to 63 percent.
According to SimilarWeb, installs across the four apps in the nine countries are down on average by nine percent.
Facebook of course has turned its focus onto its messaging apps as people turn to private communications between friends.
The figures in the study could suggest more time is being spent in these apps. Where Facebook users once used chat in the app, its Messenger app now counts 900 million monthly active users. Likewise, Facebook-owned WhatsApp has one billion users.
SimilarWeb noted that in the US, Messenger current installs climbed two percent over the year, while WhatsApp rose from 15 percent to 20 percent during the period.