Skylanders: Lost Islands was an app for the iPad, iPhone, iPod and Android. Like Skylanders: Cloud Patrol, it did not have a starter pack, unlike Skylanders: Battlegrounds. It was a free game, but it was only available in some countries like Australia, Canada, Europe, and the US.
On the 22nd of August 2017, it was announced that Skylanders Lost Islands would be removed from the App store on November 1st. 
In Skylanders: Lost Islands, the war against Kaos has destroyed Mabu villages and towns. Now, the Mabu need the players' help to find a new home. With the help of the Skylanders, players must build the Mabu a new home on the Lost Islands.
Skylanders: Lost Islands was a game where players had to use gold, gems, and energy to perform tasks and build homes for the Mabu. Use gold and gems to build houses. Each house built would add to the players' Mabu population. When players get a certain amount of Mabu, they'd use them to build community buildings such as banks and post offices. Houses and communities give the player experience over time, which would be collected to advance in levels and unlock new features. Gold and gems could also be used to buy production items such as adventure balloons and energy fields, or decorations such as trees or roads.
Energy was needed for all tasks that require Skylanders. Some of these tasks included scattering sheep, destroying troll camps, and going out on adventures. Energy was bought with gems or grown in Energy Fields or Radiant Energy Fields, where players harvested plants to gain energy. Gold, however, was obtained by completing tasks that require energy. Different kinds of experience can be obtained by doing any tasks.
Similar to Skylanders: Cloud Patrol, there was the Element of the Day function. Using a Skylander that matched the Element of the Day would let the player's Skylander get extra experience and coins.
Sometimes players received quests from Companions or high-level Skylanders . Quests varied in difficulty and became progressively harder. Completing quests rewarded the player with experience, coins, and more.
- Although they are two different characters, Gorm and Tuk were counted as one companion in Lost Islands.
- Unlike the Skylanders and the Mabu Citizens, the Companions didn't give a cheer when they were poked by the user. However, when they are poked, a "boing" sound effect is played instead.
- The golden coins had an image of Trigger Happy on them.
- The crop Moss Stash is a pun on "moustache."
- Although not birds themselves, Whirlwind and Flashwing were capable of using the Bird House in this game.
- After the game's final update, it was left with a total of 214 Skylanders, 50 companions and 20 villains.
- Unlike the other Skylanders, King Cobra Cadabra was hidden and can only be unlocked through codes or his figure on the Bluetooth Portal of Power. He was also the last Skylander to be included in the game.
- Several aspects of Lost Islands were used in Skylanders: SuperChargers including the Wishing Well.
- Gnarly Barkley was the only Skylander before SuperChargers who has not had an appearance in this game.
- Blizzard Chill, Sure Shot Shroomboom, Full Blast Jet-Vac and Fizzy Frenzy Pop Fizz appeared as variants in this game.
- This was the longest living spin-off app of the Skylanders series, lasting from October 2012 to November 2017, slightly over 5 years. However, the game stopped getting updates in May 2015, meaning its life span was technically only around half of that.