This week's 5 hot new apps: The literary world is your Oyster; Affordable navigation with Viago; more

"Netflix for books" service Oyster was made available for Android users Tuesday in a major update to the app. Along with the extended availability, developers have added new features like redesigned book detail pages that adjust color palette based on the title and access to related publications and book groups based on similarity. These fit nicely with existing capabilities like cross-device syncing and user-selected collections. As a way to help customers more thoughtfully choose their next read, the app now also provides editor's notes for top titles from critics at Huffington Post, The New Yorker, NPR, The Paris Review, Poets & Writers and others. The app costs $9.95 per month, but a free trial is available.

No doubt feeling pressure from free-to-use competitors like Google Maps and Waze, Garmin has unpackaged features from its $30 StreetPilot navigation software into a more affordable and simply designed offshoot called Viago. For 99 cents until July 13 and $1.99 after that, the app delivers its basics, such as worldwide maps, lane assistance, realistic junction views, speed limits, weather and traffic. The program also has buy-in functions that users can pay more for, including Real Directions, which gives instructions based on physical landmarks rather than streets and roads. Customers can also pay an additional fee to download navigable maps, something the free apps do not provide.

Developers of the next generation of apps have an eye on personal health, and Paris-based Smokio provides the conscious e-cig smoker with intelligence that could lead to healthier behavior. The creators are careful not to brand the system as a quitting program but rather an informational tool. Every puff from the Smokio e-cig is logged on the app via Bluetooth, and the data is compiled into useable facts, such as where you vape, when you vape and the equivalent nicotine consumption of traditional cigarettes. There is even a feature that shows how much money you saved based on what you would normally pay.

Hotel chain Marriott revealed plans for an app this week that it hopes will connect it to the younger generation of workers, those weaned on Facebook and living in a Tinder world, according to fastcoexist.com. Six Degrees, created in a joint effort with the MIT Mobile Experience Lab, will access LinkedIn profiles--once permitted, of course--and provide users with matches based on interests. Need a jogging partner? Karen ran a half-marathon recently. Want to hit the hotel bar? Andy loves to socialize. While the app may seem prying, it only uses as much information as your LinkedIn profile imparts and doesn't provide photos or last names. On-site testing at a Marriott location is planned for this month and will extend to 12 pilot locations if successful.

Looking to expand its userbase, popular brain training app Lumosity was made available to Android users Friday. Designed "by neuroscientists to train memory, attention and more," the gamified intelligence program has been available in revamped form on iOS since last year, and the company has been around since 2007. However, with the extension to Android devices, the app has opened itself up to a drastically larger potential user pool. And as the most popular education app for iPhones in 72 countries and the iPad in 111 countries, the company fully expects to remain at the top of the class.