goodroi - 1:29 pm on Aug 12, 2013 (gmt 0)
From my perspective too many webmasters are overly focused on the historic Google ranking factors. They are not paying attention to how Google is changing to a more holistic approach to ranking. IMHO Google is trying to pull in outside factors (like usage and direct traffic) into the secret formula because they tend to be harder to manipulate.
Personally I tend to stay away from mobile apps when trying to generate traffic signals. Mobile apps can drive direct traffic but in my experience they can also divert mobile web traffic away from the main site and towards the mobile app. Of course you could argue that mobile apps can boost branding which will then later boost type in traffic and branded search terms.
From my testing I do see a positive impact on Google rankings when I boost external traffic flows (not sure if this is direct or indirect correlation).
To encourage more direct traffic to my website from mobile users I do make sure the website is mobile friendly. Also I take the time to make nice apple icons to encourage repeat visits from mobile users who bookmark it (and also to stop those pesky 404 icon errors).