The Greenland GPS app, available for free for Apple and Android, contains maps and trail guides for the 160-kilometer Arctic Circle Trail (between Kangerlussuaq airport and the town of Sisimiut on the west coast, with lakes, fjords and 300- to 1,000-meter-high mountains) and for trails in the South Greenland Trails area (between the airport at Narsarsuaq and the town of Narsaq, ranging from flat fields to 1,700-meter peaks and featuring Viking ruins).

A phone’s GPS will update...

Visitors can learn the art of making chocolate in numerous workshops (each offered in English) at the headquarters of Swiss chocolatier Cailler (Rue Jules Bellet 7, Broc, Fribourg, Switzerland; phone +41 26 921 59 60).

In the 3-hour “Bean to Bar” workshop (CHF77 [near $80]), participants learn the entire process, from roasting beans to tempering the liquid chocolate, each forming their own bar. A 3-hour “Truffles” class (CHF77) works with dark, milk and white...

With United Airlines’ Gift Card Exchange, you can trade the value of unused gift cards for United MileagePlus miles. Only gift cards from approved retailers, including Target, Walmart and rival airlines American and Southwest, can be exchanged (a complete list is available online).

Each gift card must have a balance of at least $15, and multiple gift cards can be exchanged at one time. To qualify, you must have had a MileagePlus account for at least 90 days with no negative...